New lead in 1970s assassination of NSW anti-drugs crusader Donald Mackay

A man who allegedly witnessed the 1977 murder of anti-drugs crusader and Liberal Party candidate Donald Mackay, says he never came forward because he feared the law.

His claims are being investigated by police looking into the cold case, the Daily Telegraph has reported.

Nobody has ever been charged with Mackay's murder, and his body has never been found.

Melbourne man James Bazley, a gangland hitman, was convicted of conspiring to murder the staunch anti-drugs crusader.

It is believed Mackay was killed on the order of mafia figures who sought to silence his vocal opposition to the drugs trade.

The new witness, whose name has not been reported, said he saw several men shoot Mackay in Griffith on the evening of July 15, 1977.

He said the attackers had "turned their attention" to him after shooting Mackay, and that it was a "miracle" he was still alive.

He claimed corrupt police had been involved in the shooting, which had kept him from coming forward.

Former Victorian Police homicide chief Peter Halloran was sceptical about the witness's motives.

"You have to wonder why this supposed witness to the murder is telling people about it now, but it is still a lead that needs to be followed up," he said.

He said there had never been any evidence of anybody except Bazley being present at the shooting, but that it was "possible" others had been present.