House Intelligence Chairman Devin Nunes told reporters on Wednesday that members of the Donald Trump transition team, and potentially Trump himself, were under surveillance during the Obama administration following November's election, according to "sources."
The surveillance appears to have been legal and "incidental," said Nunes. It also does not appear to have been related to concerns over collusion with Russia.
Nunes made his announcement at a news conference two days after the director of the Federal Bureau of Investigation, James Comey, confirmed to a hearing of his committee that it was conducting a criminal investigation of potential links between Trump associates and Russia, as Moscow sought to influence the 2016 U.S. election to benefit Trump.
"I recently confirmed that on numerous occasions the intelligence community ... collected information about U.S. citizens involved in the Trump transition," Nunes told reporters.
Nunes said he obtained the information from a source he did not identify in any way. Democrats on the committee said they had not been consulted about the information before the news conference.
"I want to be clear, none of this surveillance was related to Russia or the investigation of Russian activities or of the Trump team," Nunes said.
However, Nunes said later that he could not be sure that other information existed elsewhere related to Russia.
U.S. intelligence agencies have accused Russia of seeking to influence the presidential election in Trump's favor against Democratic candidate Hillary Clinton by hacking computer systems and spreading disinformation. Russia denies the allegations.
Nunes said he was "very concerned" about whether U.S. intelligence agencies were spying on Trump. He said he had briefed Republican House Speaker Paul Ryan and planned to share the information with the White House later on Wednesday.
Nunes spoke to reporters just before Trump spokesman Sean Spicer gave his daily news briefing at the White House.
Spicer read some of Nunes' statement during the briefing.
"I do think it is a startling revelation, and there's a lot of questions that need to get asked," Spicer said.
(Reporting by Patricia Zengerle, additional reporting by Doina Chiacu and David Alexander; editing by Grant McCool)
Additional reporting from Reuters.