Former FBI Director James Comey wrote in a memo that President Donald Trump asked to end to the investigation of national security adviser Michael Flynn, according to a source familiar with the matter.
Comey was so appalled by the request that he wanted to document it, the source said. Comey shared it with FBI senior officials, according to the source.
"I hope you can let this go," Comey wrote, quoting the President. CNN has not viewed the memo but the source described it to CNN.
The memo is the clearest sign yet of potential interference by Trump with the investigation into whether members of his campaign team colluded with Russian officials.
Writing the memo was "not out of character," especially if he was concerned about the legality or moral issues, according to a former Justice Department official.
The New York Times first reported news of the memo.
Multiple White House officials refuted the claim on Tuesday, including one who said a "conversation of that nature" did not happen.
"While the President has repeatedly expressed his view that General Flynn is a decent man who served and protected our country, the President has never asked Mr. Comey or anyone else to end any investigation, including any investigation involving General Flynn," a White House official said in a statement. "The President has the utmost respect for our law enforcement agencies, and all investigations. This is not a truthful or accurate portrayal of the conversation between the President and Mr. Comey."
Trump has looked to stay loyal to Flynn, despite the fact that he fired his top national security aide in February after it became clear that he did not properly disclose the nature of conversations he had with Russian officials.
Trump, in a series of public comments and interviews, has suggested that Flynn was being mistreated and has heralded him as a good man.
"Gen. Flynn is a wonderful man. I think he has been treated very, very unfairly by the media, as I call it, the fake media in many cases," Trump said in February. "And I think it is really a sad thing that he was treated so badly."
Lawmakers want to hear from Comey
Reaction from Capitol Hill was swift, with Republicans and Democrats alike demanding answers from Comey.
Sen. Lindsey Graham, a South Carolina Republican, said Tuesday that the former FBI director should testify before Congress about his conversation with Trump.
And Sen. Dianne Feinstein told reporters that she "absolutely" thinks Comey should testify before the full Senate Judiciary Committee on the conversation.
"I believe we should begin to hold hearing as a full committee on this," she said.