The top White House lawyer has cooperated extensively with the special counsel investigating Russian interference in the 2016 US election, sharing detailed accounts about episodes at the heart of the inquiry into whether Donald Trump obstructed justice, the New York Times reported on Saturday.

Citing a dozen current and former White House officials and others briefed on the matter, the newspaper said White House counsel Donald McGahn had shared information, some of which the investigators would not otherwise have known about.

Trump has repeatedly denounced the investigation into whether his campaign colluded with Moscow as a “witch hunt”.

“The president and Don have a great relationship,” White House press secretary Sarah Sanders said in a statement on Saturday. “He appreciates all the hard work he’s done, particularly his help and expertise with the judges, and the supreme court.”

Others in the White House have described the relationship as strained.

Trump subsequently tweeted his own response to the report, writing: “I allowed White House counsel Don McGahn, and all other requested members of the White House staff, to fully cooperate with the special councel [sic]. In addition we readily gave over one million pages of documents. Most transparent in history. No Collusion, No Obstruction. Witch Hunt!”

He subsequently deleted the tweet and reissued it with the spelling mistake corrected.

McGahn cooperated with Robert Mueller’s team as a regular witness, a person familiar with the matter told Reuters, as the White House asked many staffers to do. McGahn was not subpoenaed nor did he speak under any kind of agreement.

The person also said he did not believe McGahn provided Mueller with incriminating information about Trump. McGahn provided the facts but nothing he saw or heard amounted to obstruction of justice by Trump, the person told Reuters.

According to the Times, in at least three voluntary interviews with investigators that totalled 30 hours over the past nine months, McGahn described both Trump’s anger toward the Russia investigation and the ways in which the president urged him to respond to it.

The newspaper reported McGahn’s motivation to speak with the special counsel as an unusual move in response to a decision by Trump’s first team of lawyers to cooperate fully. But it also said McGhan feared he could be placed in legal jeopardy because of decisions in the White House that could be construed as obstruction of justice.

McGahn, the newspaper said, shared information on Trump’s comments and actions during the firing of FBI director James Comey and the president’s obsession with putting a loyalist in charge of the inquiry, including his repeated urging of Attorney General Jeff Sessions to claim oversight of it.

The newspaper said McGahn was also centrally involved in Trump’s attempts to fire Mueller, which investigators might not have discovered without him.

McGahn told investigators he never saw Trump go beyond his legal authorities.

A source close to the president told Reuters the extent of McGahn’s cooperation was “a tactical or strategic mistake” because McGahn should have been covered by executive privilege. The person also said Trump is not worried because he does not feel he did anything wrong.

William Burck, McGahn’s personal lawyer, did not immediately respond to a request for comment.

Trump’s former personal lawyer, John Dowd, told Reuters he was aware McGahn had spoken to Mueller’s team.

“Lot to cover,” Dowd said in text message. “Did a great job. McGahn was a strong witness for the president according to Burck and debriefs of DM [Donald McGahn]. Not aware of any of the alleged apprehensions manufactured by the NYT.”

Dowd said a decision was made by the president’s legal team for McGahn to cooperate. Former White House lawyer Ty Cobb, who resigned in May after joining the administration last summer to assist the president with the Russia investigation, did not immediately respond to a request for comment.

Peter Carr, a spokesman for Mueller, declined to comment.