DONALD Trump says he never asked former FBI director James Comey to stop investigating his former national security adviser Michael Flynn.

Mr Flynn has become the first member of Mr Trump’s administration to plead guilty to a crime uncovered by special counsel Robert Mueller’s investigation into Russian attempts to influence last year’s US presidential election.

Mr Flynn was charged with lying to the FBI.

I never asked Comey to stop investigating Flynn. Just more Fake News covering another Comey lie! — Donald J. Trump (@realDonaldTrump) December 3, 2017

Mr Trump fired Mr Comey from his job as FBI director in May, sparking a political firestorm as critics claimed he was trying to meddle in the Russia investigation. That led directly to the appointment of Mr Mueller.

“I never asked Comey to stop investigating Flynn. Just more Fake News covering another Comey lie!” Mr Trump tweeted.

Mr Trump also attacked his own FBI in a series of tweets, saying the law enforcement agency’s reputation is “in tatters — worst in history!” He also promised to “bring it back to greatness”.

Tainted (no, very dishonest?) FBI “agent’s role in Clinton probe under review.” Led Clinton Email probe. @foxandfriends Clinton money going to wife of another FBI agent in charge. — Donald J. Trump (@realDonaldTrump) December 3, 2017

People who lost money when the Stock Market went down 350 points based on the False and Dishonest reporting of Brian Ross of @ABC News (he has been suspended), should consider hiring a lawyer and suing ABC for the damages this bad reporting has caused - many millions of dollars! — Donald J. Trump (@realDonaldTrump) December 3, 2017

Report: “ANTI-TRUMP FBI AGENT LED CLINTON EMAIL PROBE” Now it all starts to make sense! — Donald J. Trump (@realDonaldTrump) December 3, 2017

The president was responding to reports that a veteran FBI counterintelligence agent was removed from special counsel Robert Mueller’s team investigating Russian election meddling because of anti-Trump text messages.

“Tainted (no, very dishonest?) FBI ‘agent’s role in Clinton probe under review.’ Led Clinton Email probe,” Mr Trump tweeted.

The agent had also worked on the investigation of Hillary Clinton’s use of a private email server.

The president also retweeted a tweet suggesting FBI director Chris Wray “needs to clean house”.

It comes as Mr Trump’s personal lawyer has taken responsibility for a tweet about the firing Michael Flynn, which raised more questions about whether there had been attempts to impede the Russia investigation.

Mr Comey claims Mr Trump asked him to “go easy” on Mr Flynn when he was still FBI director. Importantly, the tweet in question suggests Mr Trump knew Mr Flynn had lied to the FBI - i.e. committed a crime - when he made that request.

Mr Trump says he never asked Mr Comey to ease up on Mr Flynn.

I had to fire General Flynn because he lied to the Vice President and the FBI. He has pled guilty to those lies. It is a shame because his actions during the transition were lawful. There was nothing to hide! — Donald J. Trump (@realDonaldTrump) December 2, 2017

In an interview in the US on Sunday, Mr Trump’s lawyer John Dowd said he had drafted the tweet and it was “my mistake”.

“I’m out of the tweeting business,” Dowd told Axios. “I did not mean to break news.”

Trump’s tweets have raised alarm among both Democratic and Republican lawmakers, with warnings Trump could be wading into “peril” with his comments.

“I would just say this with the president: There’s an ongoing criminal investigation,” Republican Senator Lindsey Graham said on the CBS program Face the Nation.

“You tweet and comment regarding ongoing criminal investigations at your own peril,” he added.

The Russia matter has dogged Trump’s first year in office, and this weekend overshadowed his first big legislative win when the Senate approved a tax cuts bill.

Flynn was the first member of Trump’s administration to plead guilty to a crime uncovered by special counsel Robert Mueller’s wide-ranging investigation into Russian attempts to influence the 2016 US election and potential collusion by Trump aides.

Russia has denied meddling in the election and Trump has said there was no collusion.

Comey, who had been investigating the Russia allegations, was fired by Trump in May. He told the US Senate Intelligence Committee in June he believed his dismissal was related to the Russia probe, and said Trump asked him to end the investigation of Flynn.