It was a crime that shocked the nation and still casts a shadow over the small country town of Griffith, in the New South Wales Riverina. Furniture salesman and outspoken anti-drugs campaigner Don Mackay was shot dead outside outside a Griffith pub in 1977 on the orders of local Mafiosi.
The body of 43-year-old Mackay, who had been named at a recent drugs trial as a police informant, has never been found. Now detectives are making a "last-ditch effort" to solve the mystery, and the NSW Government is offering a A$200,000 ($257,800) reward for information leading to its discovery.
Last Sunday was the 35th anniversary of Mackay's murder.
Police have received many tip-offs over the years. They are now analysing a batch of letters and other documents sent to them anonymously. There are hopes they could lead to a breakthrough.
Griffith, a fruit and wine-growing area with a large Italian population, has long been home to a cell of the Calabrian Ndrangheta, or Honoured Society. A 1979 royal commission named six of its members as being involved in Mackay's killing. Another man, James Bazley, served 15 years for conspiracy to murder, but no one has been charged with the murder.
Mackay's wife, Barbara, died in 2001. His son, Paul, who runs his furniture business, said: "It is still important for the people of Griffith, as well as our family, to see those people ... brought to justice."
Mackay, a Liberal Party candidate, tipped police off about a huge marijuana plantation at Coleambally, near Griffith, which led to four men being convicted.
Two days before his murder, he told a reporter he believed he was a marked man. His bloodstained minivan was found in the pub car park, with his keys on the ground and three .22 calibre cartridge shells lying nearby.
Detective Superintendent Michael Rowan, the Griffith local area commander, said: "We are confident that someone knows what happened to Mr Mackay's body."