U.S. President Donald Trump's former attorney asserts that Trump knew in advance about a 2016 meeting between his campaign staff and Russians who claimed to have compromising information on Hillary Clinton, according to NBC News.
Cohen is willing to make that assertion to special counsel Robert Mueller, NBC said. Mueller is investigating whether the Trump campaign colluded with the Kremlin during the U.S. presidential election.
U.S. intelligence services are in broad agreement that Russia directly interfered with the election.
President Trump's current attorney, Rudy Giuliani, told NBC that "Michael Cohen is not credible."
"Michael Cohen can't be believed unless it's corroborated five times," Giuliani said. "I talked to the president about this at length before as well as other witnesses and it's not true. Why would you expect it would be true from someone like Cohen? A lawyer who would tape their own client is a lawyer without any character."
The White House did not immediately respond to a CNBC request for comment.
Donald Trump Jr. has repeatedly denied that he told his father in advance about the 2016 Trump Tower meeting.
Trump Jr. agreed to the meeting at Trump Tower so that he could explore a Russian offer of supposedly damaging information on Democratic presidential candidate Clinton. His brother-in-law, Jared Kushner, and then-campaign manager Paul Manafort also attended that meeting in early June 2016.
Manafort is scheduled to go on trial next week on bank fraud and tax charges related to his work for a pro-Russia political party in Ukraine. Mueller is prosecuting that case.
Thursday night's news broke hours after the Wall Street Journal reported that the chief financial officer of the Trump Organization, Allen Weisselberg, has been subpoenaed by a federal grand jury investigating Cohen for possible crimes.
Lanny Davis, a lawyer for Cohen, said he had no comment but told CNBC: "I have to wonder why the Trump people would put that out. It was not from us."
Word that Cohen is willing to cooperate with Trump's most significant current threat — the Mueller investigation — underscores the fact that the president and his former personal lawyer and longtime fixer are now in open warfare.
The stakes for both men are high: the legal fate of each hangs in the balance, and Trump's presidency potentially does as well.
Trump has repeatedly raged that the Mueller probe is a ''witch hunt'' and that there was ''no collusion'' with Russians by his campaign.
Last week, it was disclosed that Cohen had secretly recorded Trump when the two men were discussing a hush-money payment for a story involving Playboy model Karen McDougal in September 2016.
McDougal claims she had an affair with Trump beginning in 2006. Trump was already married at that time to Melania Trump, currently the first lady of the United States.
Audio of that tape includes Cohen mentioning to Trump that he and Trump Organization CFO Weisselberg had discussed setting up a company to make that payment.
The White House has denies Trump had sex with her, and Giuliani says no payment was ever made by Trump for her story.