Dr Alan Murray, originally from Glasgow, said that “under no circumstances” was he involved in the death of Blair Peach, 33, a special needs teacher from New Zealand who suffered a fatal head injury in April 1979 when police clashed with demonstrators in London’s Southall. They were protesting against a National Front election meeting in the predominantly Asian community.

“I was not involved in the death of Blair Peach. I’m as certain as I can be,” he said, adding: “I think it was a dreadfully tragic incident and I’m very sad I was part of it.”

Suspicion fell on Inspector Murray, then 29 years old and head of Number One Unit in the Metropolitan Police’s Special Patrol Group (SPG), after eleven witnesses claimed to have seen members of the elite SPG beating Mr Peach.

None of the officers was identified, however, and initial attempts to press charges against the SPG were abandoned after the director of public prosecutions decided there was insufficient likelihood of convictions. An inquest later returned a verdict of “misadventure”.

In an interview for the BBC’s Newsnight programme broadcast last night, Dr Murray, now 59, reiterates a long-held conviction that he was the victim of a police stitch-up. He claims sources in the Met, under pressure to find a culprit, leaked information implicating him and his men.

He also said he has no memory of seeing Mr Peach that day and denies he used his baton on anyone.

Parallels have been drawn between the controversial Peach case and the death in April this year of Ian Tomlinson, a newspaper seller who was on his way home during the G20 protests when he was attacked from behind and knocked to the ground by a police officer in riot gear. To date, no-one has been charged.

The shocking images of police brutality captured on video that day reminded Dr Murray of the street battles in Southall.

“It was 30 years to the month after the death of Blair Peach and there were so many similarities which show we haven’t moved on very far,” he said.

This summer, MPs called for a secret Met report into Mr Peach’s death to be published without censorship, in a bid to “restore confidence” in the police.

Commander John Cass, who investigated the case in 1979 as the head of the Met’s complaints bureau, was believed to have produced a report that identified several officers as possible suspects in the killing and accused others of thwarting his inquiries.

The Met has now said it will release the Cass report before the end of the year.

Earlier this month, it also emerged that police had secretly reopened the file into Peach’s death ten years ago.

Born in Glasgow and brought up in Fort William, Murray moved to England when he was 14. Praised as an “exceptional” officer, he was made an inspector aged just 25 and looked set to end his career as a Met commander, or even commissioner.

Instead, he quit the force following the inquest into Mr Peach’s death and is now a lecturer in accounting and corporate social responsibility at Sheffield University.

“I’m still here and I’ve made a new career for myself,” he said. “Blair Peach was killed. And that’s something I think about, often.”