The special counsel appointed to investigate Russian influence in the 2016 US presidential campaign is now examining whether Donald Trump tried to obstruct justice, according to a report.

Mark Corallo, a spokesman for Mr Trump’s personal lawyer, responded to the Washington Post’s report, saying: “The FBI leak of information regarding the president is outrageous, inexcusable and illegal.”

The Post report cites anonymous sources who were briefed on requests made by investigators.

It was not known whether the FBI was the source of the information.

Accusations of obstruction arose last month when President Trump fired FBI director James Comey.

Mr Comey told a Senate hearing last week that he believed he was sacked “because of the Russia investigation”, being carried out by special counsel Robert Mueller.

Mr Comey also said he had told Mr Trump that he was not under investigation.

The Washington Post and The New York Times both said Mr Mueller was seeking interviews with three Trump administration officials who were not involved in his campaign – director of national intelligence Dan Coats, head of the National Security Agency Michael Rogers and Richard Ledgett, the NSA’s former deputy director.

On Wednesday Mr Mueller met the leaders of the Senate Intelligence Committee in an effort to ensure their investigations did not conflict.

The committee leaders said in a statement that they “look forward to future engagements” with Mr Mueller.

Committee chairman Richard Burr, and Senator Mark Warner of Virginia, the panel’s top Democrat, did not provide any other details, but an aide familiar with the meeting said it was held to discuss the investigations, including ways that the parallel inquiries did not interfere with one another.

The meeting comes a day after politicians questioned Justice Department officials about the probe and Mr Mueller’s independence, and after a friend of Mr Trump said the White House was considering firing Mr Mueller.

Deputy attorney general Rod Rosenstein, who appointed Mr Mueller last month, testified on Tuesday that he had seen no evidence of good cause to sack him.

Meanwhile Senate Judiciary Committee chairman Charles Grassley said his panel would investigate the removal of Mr Comey and “any alleged improper partisan interference in law enforcement investigations”.

Mr Grassley announced the investigation in a letter to California senator Dianne Feinstein, the panel’s top Democrat.

Mr Grassley’s office said the letter was in response to a recent letter from Ms Feinstein requesting that the committee seeks details from senior FBI leadership about Mr Comey’s interactions with Mr Trump before he was sacked.

The letter said the investigation would also probe Mr Comey’s testimony that Loretta Lynch, as former president Barack Obama’s attorney general, had directed him to describe an FBI probe into Hillary Clinton’s email practices as merely a “matter” and to avoid calling it an investigation.