The Scottish Police Federation (SPF), which represents rank-and-file officers, had previously questioned the former judge’s impartiality, citing concerns over his private meetings with Mr Bayoh’s family.

Mr Bayoh, a 31-year-old father of two, died in May 2015 after being restrained by six police officers on a street in Kirkcaldy. The public inquiry has been examining the events leading to and surrounding his death, the subsequent police investigation, and whether race played a part.

In a letter to Deputy First Minister Kate Forbes, Lord Bracadale confirmed his resignation, saying it followed the SPF’s move to seek a judicial review of his decision to remain in post — a hearing that had been scheduled for next month.

The dispute began in April, when the SPF first raised concerns about his meetings with the Bayoh family. In June, the federation made a formal application for Lord Bracadale to recuse himself, but he ruled in August that he would continue to chair the inquiry.

Following his resignation, the SPF said his position had become “untenable” but described the situation as “unfortunate for all those involved in the inquiry”.

In his resignation letter, Lord Bracadale wrote: “As the judicial review process developed it became clear that the concerns about my conduct had not been allayed by my decision and that the criticisms have persisted.

“As a result, it is now clear to me that many of the core participants have lost confidence in my conduct of the Inquiry to such an extent that it cannot be retrieved.”

Lord Bracadale added: “I am concerned that the majority of core participants would have no confidence in the findings of any report prepared by me.

“I consider that that, in turn, would be likely to have a damaging effect on public confidence in the findings of a report prepared by me and recommendations flowing from it.

“In my view the best interests of the inquiry would be served by the appointment of a new chair to whom the existing evidence, all of which is available on tape and transcript, would be available.”