US President Donald Trump is being investigated by special counsel Robert Mueller for possible obstruction of justice, the Washington Post has reported.
Mr Mueller is investigating alleged Russian interference in the 2016 US presidential election and possible collusion with the Trump campaign.
Former FBI Director James Comey told Congress last week he believes he was fired by Mr Trump to undermine the agency's Russia probe.
The Washington Post said Dan Coats, the director of national intelligence, Mike Rogers, the head of the National Security Agency, and Richard Ledgett, the former deputy director at the NSA, had agreed to be interviewed by Mr Mueller's investigators as early as this week.
The obstruction of justice investigation into Mr Trump began days after Mr Comey was fired on 9 May, according to people familiar with the matter, the Post said.
Mr Trump's legal team quickly denounced the report.
"The FBI leak of information regarding the President is outrageous, inexcusable and illegal," a spokesman for Mr Trump's legal team, Mark Corallo, said.
A spokesman for Mr Mueller's team declined to comment.
Several legal experts told Reuters that Mr Comey's testimony last week that Mr Trump expected loyalty and told Mr Comey he hoped he could drop an investigation of a former top aide could bolster obstruction of justice allegations against Mr Trump.
Mr Comey would not say in his testimony last week whether he thought the president sought to obstruct justice, but added it would be up to special counsel Mr Mueller "to sort that out."
After Mr Comey's testimony, Mr Trump said he had been vindicated because his former FBI director confirmed telling Mr Trump on three occasions that he was not under investigation.
While a sitting president is unlikely to face criminal prosecution, obstruction of justice could form the basis for impeachment. Any such step would face a steep hurdle as it would require approval by the US House of Representatives, which is controlled by Mr Trump's fellow Republicans.