Washington - In an ominous warning, President Donald Trump declared on Friday that fired FBI Director James Comey had better hope there are no "tapes" of their private conversations. Trump's tweet came the morning after he asserted Comey had told him three times he wasn't under FBI investigation.Comey has not confirmed Trump's account, which concerns the FBI's probe of Russia's interference in the 2016 presidential election and allegations of Trump campaign collaboration with the Russians.And on Friday, a person close to the former director recounted a Comey-Trump dinner in January in which Trump asked for a pledge of loyalty. Comey declined, instead offering "honest." When Trump then pressed for "honest loyalty," Comey told him, "You will have that," recounted the Comey associate.White House spokesperson Sarah Huckabee Sanders disputed that report and said the president would "never even suggest the expectation of personal loyalty." Officials did not immediately respond to questions about whether Trump recorded his discussions with the FBI director.Details of the dinner were first reported by The New York TimesTrump, in an interview on Thursday with NBC News, had this version: "I said, 'If it's possible, would you let me know, am I under investigation?' He said you are not under investigation." Trump said the discussions happened in two phone calls and at a dinner in which Comey was asking to keep his job.The president's Twitter comments on Friday again raised the spectre of Richard Nixon, whose secretly taped conversations and telephone calls in the White House ultimately led to his downfall in the Watergate scandal. Trump's firing of Comey already has left him with the dubious distinction of being the first president since Nixon to fire a law enforcement official overseeing an investigation tied to the White House.Trump was widely known to record some phone conversations at his office in Trump Tower during his business career, sometimes remarking to aides after a call as to whether or not he had taped that one."I would note that New York is a one-party consent state, and President Trump has always abided by the law," said Sam Nunberg, a former campaign aide, noting that it is not required in New York for both parties on a call to be aware that it was being recorded.Credibility has been destroyedAssociates of the former FBI director, who remained out of sign Friday at his suburban Virginia home, said they believed any recording would validate Comey's side of the story."It would be great were they recorded," said Daniel Richman, a former federal prosecutor and now a professor at Columbia Law School.Meanwhile, the Senate's No. 2 Democrat, Dick Durbin of Illinois, said onFriday that Trump was "dangerous" and that "his credibility has been destroyed."Durbin, on "Morning Joe" on MSNBC, suggested that the president's move to fire Comey amid its Trump-Russia investigation was "dangerous because he may be obstructing justice." And he said he feared the world would no longer take Trump at his word.Trump, in his NBC interview, said he had been intending to fire Comey for months and that it had nothing to do with the Russia investigation.But he also said, "In fact when I decided to just do it, I said to myself, I said you know, this Russia thing with Trump and Russia is a made-up story, it's an excuse by the Democrats for having lost an election that they should have won."Even before Trump's provocative tweets, the White House was scrambling to clarify why Comey was fired.Chaos in the West WingThe White House initially cited a Justice Department memo criticising Comey's handling of last year's investigation into Hillary Clinton's emails as the impetus.The shifting accounts of the decision to fire Comey, whom Trump derided as a "showboat" and "grandstander," added to a mounting sense of uncertainty and chaos in the West Wing, as aides scrambled to get their stories straight and appease an angry president.Earlier Thursday, on Capitol Hill, acting FBI Director Andrew McCabe strongly disputed the White House's assertion that Comey had been fired in part because he had lost the confidence of the FBI's own rank-and-file.McCabe also pointed out the remarkable nature of Trump's version of his conversations with Comey. McCabe told a Senate panel it was not "standard practice" to tell an individual whether they are or are not under investigation.Previous presidents have made a public show of staying out of legal matters, so as not to appear to be injecting politics.The ousted director himself is said to be confident that his own version of events will come out, possibly in an appearance before Congress, according to an associate who has been in touch with him since his firing on Tuesday.Strange thoughtsTrump and Comey's relationship was strained early on, in part because of the president's explosive and unsubstantiated claims that Barack Obama wiretapped Trump Tower. Comey found the allegations confounding, according to his associate, and wondered what to make of what he described as strange thoughts coming from his new boss.The president was no kinder to Comey on Thursday, calling him names and saying he'd left the FBI in "virtual turmoil." He said that while he received a scathing assessment of Comey's performance from Deputy Attorney General Rod Rosenstein on Monday, that memo was not a catalyst for his dramatic decision as the White House had said earlier."I was going to fire Comey," Trump said. "Regardless of recommendation I was going to fire Comey."That's far different from the White House's initial account in the hours after Comey's firing. Multiple officials, including Vice President Mike Pence, said the president was acting at the behest of Rosenstein and Attorney General Jeff Sessions.The White House said Trump is weighing options for replacing Comey, a decision that could have broad implications for the future of the Russia investigation. Some senior officials have discussed nominating Rep. Trey Gowdy, the South Carolina Republican who ran the House committee that investigated Secretary of State Clinton's actions in connection with the 2012 attack on a US compound in Benghazi, Libya.McCabe characterized the investigation as "highly significant" and assured senators that Comey's firing would not hinder it. He promised he would tolerate no interference from the White House and would not provide the administration with updates on its progress."You cannot stop the men and women of the FBI from doing the right thing," he declared. He said there has been no interference so far.