Donald Trump “likely obstructed justice” when he fired FBI director James Comey during his investigation into Russian interference in the 2016 presidential election, and could face impeachment as a consequence, a new report has claimed.

The report, entitled Presidential obstruction of justice: The case of Donald J Trump, by The Brookings Institution, an established think tank, states that there are significant questions over whether the president obstructed justice.

Though any official ruling on possible obstruction cannot be made until Special Counsel Robert Mueller, who took over the probes from Mr Comey, finishes his investigation, “the public record contains substantial evidence that President Trump attempted to impede the investigations of Michael Flynn and Russian interference in the 2016 presidential election, including by firing FBI director James Comey,” the report claims.

Mr Trump fired Mr Comey in May this year while he was overseeing the investigation into possible Russian interference in the election, possible collusion between Russia and the Trump campaign, and the actions of Michael Flynn, the former National Security advisor who also advised the Trump presidential campaign – and who had communications with Russian officials that were not properly disclosed.

After being fired, Mr Comey claimed the president had sought his loyalty and said he hoped he would drop the Flynn investigation. “I took it as a direction,” Mr Comey said while giving testimony at Capitol Hill. “I took it as this is what he wants me to do,” he said, adding: “I didn’t obey that.”

The president has the authority to fire an FBI director, the authors Barry Berke, Noah Bookbinder, and Norman Eisen, write in the report, but this “does not immunize him if he takes that action with the unlawful intent of obstructing a proceeding for an improper purpose”.

In terms of obstruction however, “demanding the loyalty of an individual involved in an investigation, requesting that individual’s help to end the investigation, and then ultimately firing that person to accomplish that goal are the type of acts that have frequently resulted in obstruction convictions”, the report states.

These actions have previously led to presidents Bill Clinton and Richard Nixon, and other public officials, facing impeachment proceedings.