In one of the most dramatic developments since Mr Mackay’s 1977 murder, police – acting on an anonymous tip-off from 2011 – began excavating at a Maude Road property on Wednesday in a bid to finally solve a mystery that has cast a dark cloud over the city for 36 years.

Speaking exclusively to The Area News, Paul Mackay – the only member of the family left in Griffith – said while the discovery of his father’s remains would finally bring closure, there had been “too many false dawns” in the past. 

“We’re always hopeful but never confident,” Mr Mackay said.

“This sort of thing has happened before and we’re no more confident than we have been in the past.”

Griffith detectives, forensic officers from the Australian Federal Police and a host of other agencies scoured the property for the past two days, draining a dam and focusing on a former pig sty.

A police source told The Area News authorities were most interested in a small patch of land on the farm – about 50 metres by 30 metres – and started “digging a deep hole” there at about 3pm yesterday.

Griffith Police commander Michael Rowan said the search was set down for between five and seven days, describing the information that led police to the site as “credible”.

“It was information that came to the Griffith station in December 2011 from an anonymous source and indicated where the body could be located,”  Superintendent Rowan said.

“We’ve made extensive inquiries since then to support the tip-off and we’re now in a situation where we cannot discount it – it’s serious enough for us to launch such a large-scale search.

“This is Australia’s first political assassination and very close to the hearts of Griffith people.

“We owe it to them and the family to do this properly.” 

The property, which remains under 24-hour guard, is owned by elderly farmer Con Fattore, who is not believed to be a suspect in the case.

Mr Fattore, 79, who does not live on the property, refused to comment on how long he had owned the property or the nature of the search.

“It’s my property but ask the police. I got nothing to do with it,” he said.

Last July, the state government doubled the reward to $200,000 for information leading to Don Mackay’s remains.

Mr Mackay, 43, went missing from the car park of the Griffith Hotel on July 15, 1977.

His body has never been found, but extensive police investigations and a 1984 coronial inquest concluded that he had died of wilfully inflicted gunshot wounds.

It is widely believed Melbourne hitman James Bazley was the trigger-man but despite ailing health, he has steadfastly refused to reveal to authorities where he dumped Mr Mackay’s body.

Investigations into the murder are continuing under Strike Force Fitr, comprising detectives from the Homicide Squad and Griffith Local Area Command.