It's understood a 45-year-old man, who was a neighbour of the other men, shot them on the side of quiet Scotts North Road at 10.20am.

The man then walked into a paddock at a Chamberlain Street address and took his own life.

He was located there deceased and a report was made to police.

Notorious career criminal Kevin Knowles, 49, was the first victim, he received a shotgun blast to the back of the head causing catastrophic injuries.

It's understood that the second man, also aged about 50, was run down by the neighbour driving a white van and then shot twice.

Anyone with information or dashcam footage is urged to contact Crime Stoppers on 1800 333 000.

It's believed the men were all known to each other and there had been an ongoing dispute between Knowles and his neighbour.

Late Friday afternoon homicide squad detectives were looking into the circumstances surrounding the incident.

Forensic evidence was also being collected and nearby roads were closed.

Knowles is a well known criminal and standover man.

He has been the most frequent offender appearing in the Warrnambool Magistrates Court during the past 20 years.

As of June 2020, Knowles had 41 pages of prior court appearances, involving about 300 charges, including 10 charges of failing to appear on bail as well as regular breaches of bail and community corrections orders.

He was regularly jailed.

In February 2020, a State Coroner referred the 2016 death of Warrnambool man Stephen Johnston to the Director of Public Prosecutions to consider whether criminal charges should be laid against Knowles.

Knowles and his then girlfriend Amanda Bourke were the only two people to have been at Mr Johnson's home late on the night he died.

Ms Bourke, 44, drowned at The Cutting in Killarney on January 18, 2018, when in the company of Knowles.

An article in The Standard on February 16, 2017, was submitted during an inquest into Ms Bourke's death in which magistrate Michael Coghlan was quoted saying he held grave fears for Ms Bourke's welfare.