'Art of the deal' author says he's been hacked after criticizing Trump

Schwartz, who shared co-author credit for “The Art of the Deal” with Donald Trump in 1987, said he has been victimized by a hacker in the wake of recent public criticisms he’s made of the president.

“During the past seven days my cell phone, the phone lines in my company, and my personal and business accounts have all been hacked,” Schwartz tweeted on Saturday. “I am not ready to make the tempting connection but I am alert and concerned.”

His post came three days after he repeated his claim that he alone wrote the best-selling book that lauded Trump’s entrepreneurial prowess. After Trump in a tweet had touted his own writing skills, Schwartz tweeted that the president is “incapable of reading a book, much less writing one.”

Schwartz told The New Yorker in 2016 that he was the sole author of “The Art of the Deal” and that he felt “a deep sense of remorse that I contributed to presenting Trump in a way that brought him wider attention and made him more appealing than he is.”

RELATED: Thousands protest Trump in Belgium ahead of NATO summit

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Thousands protest Trump in Belgium ahead of NATO summit
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Thousands protest Trump in Belgium ahead of NATO summit
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
A participant holds the portrait of U.S. President Donald Trump as protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
A mock figurine depicting U.S. President Donald Trump is seen as protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal TEMPLATE OUT
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. The banner reads: "No to NATO. No to War". REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal TEMPLATE OUT
Two mock figurines depicting U.S. President Donald Trump and Belgium's Prime Minister Charles Michel are seen as protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. The writing on the placard reads, 'NATO, we don't want it'. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protesters take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
A demonstrator holds a placard as protesters prepare to take part in a march against the NATO leaders summit, in Brussels, Belgium July 7, 2018. REUTERS/Eric Vidal
Protestors carry placards as they take part in a rally in Brussels on July 7, 2018, against the forthcoming NATO summit and scheduled visit of US President Donald Trump on July 11 and 12. (Photo by NICOLAS MAETERLINCK / BELGA / AFP) / Belgium OUT (Photo credit should read NICOLAS MAETERLINCK/AFP/Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
July 7th, Brussels. President Donald Trump will travel to Brussels to attend a NATO meeting scheduled for July 11-12, where it's going to be on the table more military expenditure by all NATO countries, including Belgium. This Saturday thousands of people gathering in Brussels to protest organized by the Belgium platform 'Trump not welcome here'. According to this platform, 'we don't want to take part in this military bid at the expense of social protection, tackling climate change, fighting poverty, a humane refugee policy and a diverse and inclusive society without racism, sexism, homo, and transphobia'. (Photo by Romy Arroyo Fernandez/NurPhoto via Getty Images)
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He called Trump “mentally ill” on CNN last month.

Schwartz said he will be reporting the hacking to the proper authorities.

Trump has disputed that Schwartz wrote the entire book, claiming it was a collaborative effort.

This article originally appeared on HuffPost.

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