Gregory Searle, 22, was found dead by the side of the old Hume Highway near Kilmore in January, 1985.

The murder received scant coverage in newspapers at the time, but the articles that were published claimed Mr Searle was involved with drugs and known to police.

Detective Senior Sergeant Boris Buick, from the homicide cold case and missing persons squad, said Mr Searle was last seen alive about 7.30pm on January 12 outside the Footscray Hotel on Hopkins Street. It was a Saturday night.

His body was found the next morning, about 75 kilometres away.

It appeared Mr Searle had been dragged from a car to where he was found, about 26 metres from what is now the Kilmore-Broadford Road, and there were signs of a struggle. His body was found near the 67-kilometre marker, at the gateway to a farm.

It took police two days to identify Mr Searle, an unemployed farmer who had lived in Hyde Street, Footscray.

In the five years after his death, it was reported that he had been stabbed 11 times, strangled, had his skull crushed, and been shot, execution style.

Detective Senior Sergeant Buick said Mr Searle's injuries were consistent with an assault, and appealed for those responsible to break their silence.

"We understand that circumstances change," Detective Senior Sergeant Buick said.

"There may be someone who can now come forward and provide police with information that could help solve this case, and give his family some resolution after 30 years."

In December, then-chief commissioner Ken Lay said the Victoria Police reward system would be overhauled, so that unsolved murders would be allocated $1 million lures.

Under the previous system, rewards were allocated for homicides after recommendations from investigating officers, resulting in some cold cases being subject to greater rewards than others.

As part of the new system, cold cases with existing rewards will be reviewed.

Detective Senior Sergeant Buick confirmed an application would be made to increase the $50,000 reward allocated in 1985 for information in Mr Searle's case.

In January, The Age revealed that the homicide cold case and missing persons squad would review a bungled Victoria Police relocation that had resulted in evidence linked to unsolved murders being destroyed in 1994.

The review will determine which cases were affected when exhibits were moved from Russell Street headquarters to Collingwood.

It was unclear how many cases were affected, but there were about 140 murders, dating back to the formation of the homicide squad in 1943, that remained unsolved when the move occurred.

Anyone with information regarding Mr Searle's death is urged to contact Crime Stoppers on 1800 333 000 or via crimestoppers.com.au.