Donald Trump has responded to a guilty plea by his former national security adviser Michael Flynn, saying Mr Flynn’s actions as a member of his transition team “were lawful”.
Mr Flynn has entered a plea deal and agreed to co-operate with an inquiry into alleged collusion with Russia.
The deal, for a lesser charge than he might have faced, prompted speculation that he has incriminating evidence.
The president wrote on Twitter on Saturday that he had “nothing to hide”.
On Saturday, a day after Mr Flynn’s indictment, it emerged that a veteran FBI agent had been dismissed from Mr Mueller’s team after the discovery that he had sent anti-Trump text messages.
Peter Strzok was removed from the investigation in summer, a spokesman for the special counsel’s office, told the New York Times.
Russia scandal rears its head
But any celebratory mood among administration officials would have been short-lived – dampened by a string of news reports on the Russia scandal.
In denying that Mr Flynn had acted unlawfully as part of his transition team, Mr Trump appeared to admit that he knew the former general had lied to the FBI before he fired him in February – contradicting the president’s account at the time.
Analysts say if Mr Trump knew that Mr Flynn had lied to the FBI, at a time when he appeared to pressure then-FBI director James Comey to drop the agency’s investigation into the former general, it could amount to obstruction of justice by the president.
Matthew Miller, a former Obama administration Justice Department official, said in a tweet: “Oh my god, he just admitted to obstruction of justice. If Trump knew Flynn lied to the FBI when he asked Comey to let it go, then there is your case.”
Meanwhile, the New York Times reported that it had obtained internal emails sent by Mr Trump‘s transition team that disputed the White House assertion that Mr Flynn acted alone in his contacts with Russian officials.
A White House lawyer told the paper that the adviser, KT McFarland, had meant only that the Democrats were portraying it that way.
The plea deal
Under the terms of the plea deal with Mr Mueller, Mr Flynn admitted making false statements to the FBI, a significantly lesser charge than he might have faced for illegally dealing with Russian officials.
Analysts say the deal suggests that the former general has evidence implicating one or more senior members of the Trump administration.
Several US news organisations report the very senior official now under the spotlight is Jared Kushner – Mr Trump‘s adviser and son-in-law.
Mr Trump has repeatedly denied that his campaign or transition team colluded in Russian actions. Speaking to reporters on Saturday, he said: “What has been shown is no collusion, no collusion. There has been absolutely no collusion. So we’re very happy.”