US President Donald Trump has warned fired former FBI chief James Comey against leaking material to the media.
In a tweet on Friday he said Mr Comey had “better hope that there are no ‘tapes’ of our conversations”.
Mr Comey, who had been leading an inquiry into alleged Russian meddling in the US election, was fired by the president on Tuesday.
Mr Trump has since insisted he was told by Mr Comey that he was not under investigation.
Mr Trump said he had been told twice by Mr Comey over dinner and once over the phone that he was not a target of the inquiry.
The president said: “I said: ‘If it’s possible, would you let me know: am I under investigation?’ He said: ‘You are not under investigation.'”
The FBI investigation was looking into possible collusion between Trump election campaign officials and Moscow.
Mr Trump said this week he alone was responsible for the decision to sack Mr Comey, calling him a “showboat” and “grandstander”.