Scientists have reportedly proved 'beyond reasonable doubt' that the nerve agent used on former spy Sergei Skripal came from Russia

  • Government scientists have concluded that a nerve agent used to poison double agent Sergei Skripal came from Russia, British media reported.
  • The mounting evidence could be a prelude to the British Government formally accusing Russia of mounting an assassination attempt on its soil.
  • Skripal and his daughter Yulia were poisoned on March 4, and remain in critical condition.


British government scientists have reportedly concluded "beyond reasonable doubt" that the nerve agent used to poison ex-Russian spy Sergei Skripal and his daughter Yulia last week was made in Russia.

Specialists at Porton Down, the Ministry of Defence's chemical warfare lab, reached the conclusion last night, according to The Daily Telegraph newspaper.

Tests carried out on Sunday proved "beyond reasonable doubt" that Russia made the chemical used in the attempted murder on March 4. The compound's identity has yet to be made public.

Senior government sources also told The Times newspaper that police and security officials have established "sufficient evidence" to link Russia to the attack.

The Ministry of Defence and Metropolitan Police declined to comment on the reports when contacted by Business Insider.

57 PHOTOS
UK investigates nerve agent attack on former double agent Sergei Skripal
See Gallery
UK investigates nerve agent attack on former double agent Sergei Skripal
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits prepare to examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in a critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
A picture shows the tent over the bench where a man and a woman were found in critical condition sparking a major incident on March 4 at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
Members of the emergency services in green biohazard encapsulated suits afix the tent over the bench where a man and a woman were found on March 4 in critical condition at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
A picture shows the tent over the bench where a man and a woman were found in critical condition sparking a major incident on March 4 at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
TOPSHOT - Members of the emergency services in green biohazard encapsulated suits work to afix the tent over the bench where a man and a woman were found on March 4 in critical condition at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
TOPSHOT - Members of the fire brigade in green biohazard encapsulated suits work to re-attach the tent over the bench where a man and a woman were found in critical condition sparking a major incident on March 4 at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
Members of the fire brigade get suited in green biohazard encapsulated suits to work to re-attach the tent over the bench where a man and a woman were found in critical condition sparking a major incident on March 4 at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
Members of the fire brigade are helped out of their green biohazard encapsulated suits by colleagues in white protective coveralls after an operation to re-attach the tent over the bench where a man and a woman were found in critical condition sparking a major incident on March 4 at The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 after the tent became detached. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Police officers search the home of Sergei Skripal in Salisbury who was found critically ill on a bench with his daughter on March 4 and were taken to hospital sparking a major incident on March 8, 2018 in Wiltshire, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Jack Taylor/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Police officers search the home of Sergei Skripal in Salisbury who was found critically ill on a bench with his daughter on March 4 and were taken to hospital sparking a major incident on March 8, 2018 in Wiltshire, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Jack Taylor/Getty Images)
A police officer guards a cordon on a residential street in Salisbury, southern England, on March 8, 2018 where police forensic tents are errected and police continue to work in connection with the major incident which started at The Maltings shopping centre in Salisbury on March 4. British detectives on March 8 scrambled to find the source of the nerve agent used in the 'brazen and reckless' attempted murder of a Russian former double-agent and his daughter. Sergei Skripal, 66, who moved to Britain in a 2010 spy swap, is unconscious in a critical but stable condition in hospital along with his daughter Yulia after they collapsed on a bench outside a shopping centre on Sunday. / AFP PHOTO / Ben STANSALL (Photo credit should read BEN STANSALL/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Police stand guard at the home of Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in a critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Police stand guard at Zizzil restaurant reported to have been visited by Sergei Skripal before he colapsed due to poisoning on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in a critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits prepare to examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
Pedestrians walk past a cordoned-off branch of the Italian chain restaurant Zizzi close to The Maltings shopping centre in Salisbury, southern England, on March 8, 2018 which was closed in connection to the ongoing major incident sparked after a man and a woman were found critically ill on a bench at the shopping centre on March 4 after being apparently poisoned with what was later identified as a nerve agent sparking a major incident. Britain vowed on March 8 to act 'without hesitation' if a state is found responsible for a nerve agent attack on a former Russian double agent, as police said 21 people in total had received medical treatment following the incident. Sergei Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the attack on Sunday in the sleepy south-western English city of Salisbury. / AFP PHOTO / Adrian DENNIS (Photo credit should read ADRIAN DENNIS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 09: Police officers search ahead of the visit by Home Secretary Amber Rudd to the scene at the Maltings shopping centre in where former Russian double agent Sergei Skripal and his daughter were found critically ill after exposure to a nerve agent on March 4 and were taken to hospital sparking a major incident, in Salisbury on March 9, 2018 in Wiltshire, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being exposed to an 'unknown substance'. (Photo by Matt Cardy/Getty Images)
SALISBURY, ENGLAND - MARCH 09: A police officer walks past a forensics tent over the grave of former Russian double agent Sergei Skripal's wife Lyudmila in London Road cemetery, on March 9, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being exposed to an 'unknown substance'. (Photo by Jack Taylor/Getty Images)
SALISBURY, ENGLAND - MARCH 09: A general view of a forensics tent over the grave of former Russian double agent Sergei Skripal's son Alexander in London Road cemetery, on March 9, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being exposed to an 'unknown substance'. (Photo by Jack Taylor/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Police officers dress in protective suits and breathing apparatus in London Road cemetery as they continue investigations into the poisoning of Sergei Skripal who was found critically ill on a bench in Salisbury with his daughter sparking a major incident on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Police officers dress in protective suits and breathing apparatus in London Road cemetery as they continue investigations into the poisoning of Sergei Skripal who was found critically ill on a bench in Salisbury with his daughter sparking a major incident on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
British police officers stand on duty at a cordon leading to the home of Russian spy Sergei Skripal, in Salisbury, southern England, on March 10, 2018. British soldiers were deployed on Friday to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / DANIEL LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 10: A police officer stands at a cordon at the scene connected to the Sergei Skripal nerve agent attack on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
Police tape surrounds a forensics tent covering the memorial stone to Alexander Skripal, inside the entrance of the London Road Cemetery in Salisbury, southern England, on March 10, 2018, where the wife and son of former Russian spy Sergei Skripal are buried. British soldiers were deployed on Friday to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
TOPSHOT - A member of the emergency services wearing a protective suit works at the London Road Cemetery in Salisbury, southern England, on March 10, 2018, where the wife and son of former Russian spy Sergei Skripal are buried. British soldiers were deployed on Friday to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Personnel in protective coveralls and breathing equiptment work at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Personnel in protective coveralls and breathing equiptment cover an ambulance with a tarpaulin at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. The Counter Terrorism Policing Network requested assistance from the military to remove a number of vehicles and objects from Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel in protective coveralls stand by as personnel cover ambulances in tarpaulins at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Members of the emergency services in protective coveralls and breathing equiptment cover ambulances with tarpaulins at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / DANIEL LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Personnel in protective coveralls and breathing equiptment cover an ambulance with a tarpaulin at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. The Counter Terrorism Policing Network requested assistance from the military to remove a number of vehicles and objects from Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel in protective coveralls stand by as personnel cover ambulances in tarpaulins at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Members of the emergency services in protective coveralls and breathing equiptment cover ambulances with tarpaulins and prepare to load them onto military low-loader vehicles at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Members of the emergency services in protective coveralls and breathing equiptment load a covered ambulance onto a military low-loader vehicle at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Military personnel wearing protective suits inspect a bin after an ambulance is removed from Salisbury ambulance station as they continue investigations into the poisoning of Sergei Skripal on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Military personnel wearing protective suits cover two ambulances with tarpaulin as they prepare to remove them from Salisbury ambulance station as they continue investigations into the poisoning of Sergei Skripal on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
Personnel in protective coveralls and breathing equiptment cover an ambulance with a tarpaulin to be taken away by military personnel at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. The Counter Terrorism Policing Network requested assistance from the military to remove a number of vehicles and objects from Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Military personnel wearing protective suits cover a second ambulance after removing another from Salisbury ambulance station as they continue investigations into the poisoning of Sergei Skripal on March 10, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
Personnel in protective coveralls and breathing equiptment work at the Salisbury District Hospital in Salisbury, southern England, on March 10, 2018, in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack. British soldiers were deployed on March 9 to help a counter-terrorism investigation into a nerve agent attack on former Russian spy Sergei Skripal, as speculation mounted over how London could retaliate if the Russian state is found to be responsible. Skripal and his daughter Yulia remain unconscious in a critical but stable condition following the March 4 attack in the sleepy south-western English city of Salisbury. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 10: Soldiers wearing hazmat suits seal a waste container at an ambulance depot on March 10, 2018 in Salisbury, England. The ambulance is believed to have carried former Russian intelligence officer Sergei Skripal to hospital, after he and his daughter Yulia fell ill in Salisbury city centre on March 4. Both Sergei Skripal and his daughter remain in a critical condition due to the effects of an undisclosed nerve agent. The military have been called in to assist police in their investigation and containment of the major incident. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
Police officers stand in front of a cordon in front of a branch of the chain Italian restaurant Zizzi in Salisbury, southern England, on March 11, 2018, as investigations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
A pedestrian passes in front of a police cordon in front of a branch of the chain Italian restaurant Zizzi in Salisbury, southern England, on March 11, 2018, as investigations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
SALISBURY, ENGLAND - MARCH 11: Police officers stand outside Zizzi restaurant as it remains closed as investigations continue into the poisoning of Sergei Skripal on March 11, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
SALISBURY, ENGLAND - MARCH 11: A police officer stands outside The Mill as it remains closed as investigations continue into the poisoning of Sergei Skripal on March 11, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being attacked with a nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
A police officer stands at a police cordon at The Maltings shopping centre in Salisbury, southern England, on March 11, 2018, as investigations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
A police officer stands in front of The Mill pub in Salisbury, southern England, on March 11, 2018, as investigations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. Traces of a nerve agent used in the suspected attempted murder of a Russian ex-spy have been found in a pub and a restaurant he visited, England's chief medical officer said on March 11. Sally Davies said up to 500 people who had visited The Mill pub and the Zizzi restaurant in Salisbury, southwest England, needed to wash their clothes and belongings as a precaution. The March 4 attack on Russian double agent Sergei Skripal and his daughter Yulia is being treated by detectives as attempted murder. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel, some in protective coveralls, carry equipment in a staging area at a cordon set up behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel, some in protective coveralls, talk at a staging area at a cordon set up behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
A military fork-lift vehicle is driven into an area cordoned off behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
A military low-loader vehicle is driven into an area cordoned off behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel wearing protective coveralls look at a map while others load a car onto a military vehicle in a cordoned off area behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel wearing protective coveralls look at a map while others load a car onto a military vehicle in a cordoned off area behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel wearing protective coveralls use a military fork-lift to lift a car onto a low-loader military vehicle in a cordoned off area behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel wearing protective coveralls use a military fork-lift to lift a car onto a low-loader military vehicle in a cordoned off area behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Military personnel in protective coveralls handle equipment during an operation in a cordoned off area behind a police station in Salisbury, southern England, on March 11, 2018, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack a week ago. British police hunting the perpetrators behind a nerve agent attack on a Russian former spy are examining more than 200 pieces of evidence, London said after a meeting of the UK's national emergencies committee. Counter-terror police had identified more than 240 witnesses, the Home Office interior ministry said after a meeting of the committee known as COBRA, chaired by Home Secretary Amber Rudd. Military personnel were assisting police for a third day after being called in to remove vehicles and items. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

The Skripals collapsed in a shopping centre in Salisbury just over a week ago after being exposed to nerve agent. They were taken to hospital and have been in critical condition ever since.

The elder Skripal was convicted of passing Russian state secrets to British intelligence between 1995 and 2004, before being pardoned and sent to Britain in a spy exchange in 2010.

The gathering of scientific evidence about the attack could be a prelude to the British Government formally accusing Russia of trying to kill Skripal on its territory.

According to The Times, The Telegraph, and Sky News, Prime Minister Theresa May could take that step as soon as Monday.

She could also call for new sanctions against Russian nationals close to President Vladimir Putin, the expulsion of Russian diplomats from the UK, and the withdrawal all official representation at the World Cup in Russia this summer, The Times said.

The announcement is expected to come after a National Security Council meeting on Monday, where May will take evidence from the UK's three intelligence agencies MI5, MI6, and GCHQ.

Tom Tugendhat, the chairman of the House of Commons Foreign Affairs Committee, also told BBC Radio 4's "Today" programme that the attack looks like it was state-sponsored.

24 PHOTOS
The case of Sergei Skripal's poisoning
See Gallery
The case of Sergei Skripal's poisoning
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
Chairs are seen on tables inside the Mill pub which former Russian inteligence officer Sergei Skripal and his daughter Yulia visited before they were found poisoned on a bench nearby in Salisbury, Britain, March 11, 2018. REUTERS/Henry Nicholls
SALISBURY, ENGLAND - MARCH 06: Witness Freya Church, 27, walks with a policeman near a forensic tent where Sergei Skripal, 66 and his duaghter Yulia Skripal, in her 30s, were found unconscious in Salisbury town centre two days previously on March 6, 2018 in Salisbury, England. Sergei Skripal who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010 and his daughter remain critically ill after being exposed to an 'unknown substance'. (Photo by Dan Kitwood/Getty Images)
Londoners pass-by the London newspaper Evening Standard's latest headline about ex-Russian spy Sergei Skripal's suspected poisoning by Russia in southern England, on 6th March 2018, in the capital's financial district, the City of London, England. As both Skripal and a woman believed to be his daughter Ylulia remain in a critical condition at Salisbury hospital where he was taken ill on Sunday 4th, British Counter Terrorism Police have taken over the investigation from the local Wiltshire force. The British press have been quick in blaming President Putin's involvement just weeks before his Presidential re-election. (Photo by Richard Baker In Pictures via getty Images)
Former Russian military intelligence colonel Sergei Skripal attends a hearing at the Moscow District Military Court in Moscow on August 9, 2006. Sergei Skripal, a former Russian double agent whose mysterious collapse in England sparked concerns of a possible poisoning by Moscow, has been living in Britain since a high-profile spy swap in 2010. Police were probing his exposure to an unknown substance, which left him unconscious on a bench in the city of Salisbury and saw media draw parallels to the case of Alexander Litvinenko, an ex-spy who died of radioactive polonium poisoning in 2006. / AFP PHOTO / Kommersant Photo / Yuri SENATOROV / Russia OUT (Photo credit should read YURI SENATOROV/AFP/Getty Images)
A forensics tent covers the bench, where Sergei Skripal and his daughter Yulia were found slumped, in a cordoned off area in the centre of Salisbury, Britain, March 7, 2018. REUTERS/Toby Melville
Police officers seal off the road on which Russian Sergei Skripal and his daughter have been staying in Salisbury, Britain, March 7, 2018. REUTERS/Toby Melville
Police officers stand on duty outside a restaurant which has been secured as part of the investigation into the poisoning of former Russian inteligence agent Sergei Skripal and his daughter Yulia, in Salisbury, Britain March 11, 2018. REUTERS/Henry Nicholls
SALISBURY, ENGLAND - MARCH 07: Assistant Commissioner Mark Rowley (R) and Chief Medical Officer Dame Sally Davies give a statement on March 7, 2018 in Salisbury, England. Sergei Skripal, who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010, and his daughter remain critically ill after being exposed to an 'unknown substance'. A police officer who was the first to attend the scene is now also in a serious condition in hospital. Police are treating the suspected poisoning as attempted murder by nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
Police officers stand on duty outside a pub which has been secured as part of the investigation into the poisoning of former Russian intelligence agent Sergei Skripal and his daughter Yulia, in Salisbury, Britain March 12, 2018. REUTERS/ Henry Nicholls
SALISBURY, ENGLAND - MARCH 07: Assistant Commissioner Mark Rowley leaves after giving a statement on March 7, 2018 in Salisbury, England. Sergei Skripal, who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010, and his daughter remain critically ill after being exposed to an 'unknown substance'. A police officer who was the first to attend the scene is now also in a serious condition in hospital. Police are treating the suspected poisoning as attempted murder by nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
SALISBURY, ENGLAND - MARCH 08: Forensic police officers wearing hazmat suits examine a vehicle believed to belong to Sergei Skripal on March 8, 2018 in Salisbury, England. Police investigations continue into the use of a nerve agent to poison Sergei Skripal, who was found ill in a Salisbury park with his daughter on March 4. Both Sergei Skripal and his daughter remain in critical condition in hospital. Sergei Skripal was granted refuge in the UK following a spy swap between the US and Russia in 2010. (Photo by Rufus Cox/Getty Images)
SALISBURY, ENGLAND - MARCH 07: Assistant Commissioner Mark Rowley (R) and Chief Medical Officer Dame Sally Davies give a statement on March 7, 2018 in Salisbury, England. Sergei Skripal, who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010, and his daughter remain critically ill after being exposed to an 'unknown substance'. A police officer who was the first to attend the scene is now also in a serious condition in hospital. Police are treating the suspected poisoning as attempted murder by nerve agent. (Photo by Chris J Ratcliffe/Getty Images)
Police officers stand on duty outside a pub which has been secured as part of the investigation into the poisoning of former Russian intelligence agent Sergei Skripal and his daughter Yulia, in Salisbury, Britain March 12, 2018. REUTERS/ Henry Nicholls
Londoners pass-by the London newspaper Evening Standard's latest headline about ex-Russian spy Sergei Skripal's suspected poisoning by Russia in southern England, on 6th March 2018, in the capital's financial district, the City of London, England. As both Skripal and a woman believed to be his daughter Ylulia remain in a critical condition at Salisbury hospital where he was taken ill on Sunday 4th, British Counter Terrorism Police have taken over the investigation from the local Wiltshire force. The British press have been quick in blaming President Putin's involvement just weeks before his Presidential re-election. (Photo by Richard Baker In Pictures via getty Images)
SALISBURY, ENGLAND - MARCH 07: A police tent is seen behind a cordon outside The Maltings shopping centre where a man and a woman were found critically ill on a bench on March 4 and taken to hospital sparking a major incident, on March 7, 2018 in Wiltshire, England. Sergei Skripal, who was granted refuge in the UK following a 'spy swap' between the US and Russia in 2010, and his daughter remain critically ill after being exposed to an 'unknown substance'. (Photo by Matt Cardy/Getty Images)
Former Russian military intelligence colonel Sergei Skripal attends a hearing at the Moscow District Military Court in Moscow on August 9, 2006. Sergei Skripal, a former Russian double agent whose mysterious collapse in England sparked concerns of a possible poisoning by Moscow, has been living in Britain since a high-profile spy swap in 2010. Police were probing his exposure to an unknown substance, which left him unconscious on a bench in the city of Salisbury and saw media draw parallels to the case of Alexander Litvinenko, an ex-spy who died of radioactive polonium poisoning in 2006. / AFP PHOTO / Kommersant Photo / Yuri SENATOROV / Russia OUT (Photo credit should read YURI SENATOROV/AFP/Getty Images)
A tent covers the park bench where former Russian intelligence agent Sergei Skripal and his daughter Yulia were found after they were poisoned, in Salisbury, Britain March 12, 2018. REUTERS/Henry Nicholls
A tent covers the park bench where former Russian intelligence agent Sergei Skripal and his daughter Yulia were found after they were poisoned, in Salisbury, Britain March 12, 2018. REUTERS/Henry Nicholls
A police officer stands at a cordon around the bench where former Russian inteligence agent Sergei Skripal and his daughter Yulia were found after they were poisoned, in Salisbury, Britain March 11, 2018. REUTERS/Henry Nicholls
Britain's Home Secretary Amber Rudd, accompanied by Temporary Chief Constable Kier Pritchard, visits the scene where Sergei Skripal and his daughter Yulia were found after having been poisoned by a nerve agent in Salisbury, Britain, March 9, 2018. REUTERS/Peter Nicholls
A police officer stands on duty outside a restaurant which has been secured as part of the investigation into the poisoning of former Russian inteligence agent Sergei Skripal and his daughter Yulia, in Salisbury, March 11, 2018. REUTERS/Henry Nicholls
Police officers work at a supermarket near the bench where former Russian intelligence officer Sergei Skripal and his daughter Yulia were found poisoned, in Salisbury, Britain, March 12, 2018. REUTERS/Henry Nicholls
MOSCOW, RUSSIA - MARCH 6, 2018: Pictured in this file image dated August 9, 2006, is retired colonel Sergei Skripal during a hearing at the Moscow District Court. File image/Press Office of Moscow District Military Court/TASS (Photo by TASS\TASS via Getty Images)
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

British counterterror police are leading the investigation into the attack. They are being supported by 180 military personnel, who helped remove contaminated items from the shopping centre where the father and daughter were found.

Police also found traces of the nerve agent at a restaurant and a pub in the shopping centre, and have asked the roughly 500 people who might have been in the vicinity to wash their clothes and other belongings in case they were affected.

A police officer, Sergeant Nick Bailey, was also seriously injured after responding to the Skripals. He is now "talking and engaging," UK Home Secretary Amber Rudd said.

The Kremlin has vehemently denied any involvement in the attack.

NOW WATCH: The best and worst things about the Tesla Model 3

See Also:

SEE ALSO: Putin will have broken a huge rule of the spy game if he was behind the poisoning of Sergei Skripal

READ MORE: What you need to know about nerve agent, the deadly chemical used in Sergei Skripal's attempted murder in Britain

Read Full Story