President Donald Trump asked FBI chief James Comey to drop an inquiry into links between his ex-national security adviser and Russia, US media report.
“I hope you can let this go,” Trump reportedly told Comey after a White House meeting in February, according to a memo written by the ex-FBI director.
The memo was written immediately after the meeting, a day after Michael Flynn resigned, according to media reports.
The White House has denied the allegation in a statement.
“The president has never asked Mr Comey or anyone else to end any investigation, including any investigation involving General Flynn,” it said.
An influential Republican congressman has called for the FBI to hand over all relevant documents within a week.
Jason Chaffetz, who chairs the House Oversight Committee, demanded all correspondence relating to communications between Comey and the president be presented by 24 May.
Flynn was forced out in February after he misled the vice-president about his conversations with Russia’s ambassador before Trump took office.
The latest Russian twist, first reported by the New York Times, comes a week after Trump fired Comey over his handling of the FBI investigation into Hillary Clinton’s use of a private email server while at the state department.
Comey’s dismissal sent shockwaves through Washington, with critics accusing the president of trying to thwart the FBI investigation into Russia’s alleged interference in the US election and any Moscow ties to Trump associates.
The “I” word – impeachment – has already been broached by politicians as moderate as independent Senator Angus King of Maine. If this were a Democratic-controlled House of Representatives, articles of impeachment would likely be in the drafting process.
Republicans still call the shots in Congress, however, and it’s a significant leap to get them to abandon the Trump presidency and any hope of advancing their agenda for the foreseeable future.
But some, like Senator John McCain – who said this has become a scandal of “Watergate size and scale” – are clearly wavering.
The former Republican presidential nominee is a bit of a wild card, of course.
For the rank-and-file to turn on the president will require them to admit their complicity in a failed presidency.
Since Flynn stepped down, the Pentagon has launched an investigation into whether he failed to disclose payments from Russian and Turkish lobbyists for speeches and consulting work.
Flynn’s Russian ties are under investigation by the FBI and the House and Senate Intelligence Committees, as part of wider inquiries into claims Moscow sought to tip the election in favour of Trump.