An underworld figure with links to organised crime was likely executed by two interstate men described as "guns for hire".
Athan Boursinos, 21, was allegedly ambushed by two disguised offenders beside his car in a laneway near his family home in Wollert, in Melbourne's north, on July 31.
The planned killing was ordered by an organised crime syndicate in Sydney, Victoria Police acting Detective Superintendent Mark Hatt told reporters.
He said the motive was still being investigated but confirmed Mr Boursinos was a suspect in the shooting death of Sam "The Punisher" Abdulrahim.
Mr Abdulrahim was walking with his girlfriend when the former Mongols bikie was gunned down in a Preston apartment block's underground car park on January 29.
Det Supt Hatt revealed there were likely numerous people involved in the daytime execution, adding Mr Boursinos had been involved in organised crime across the country, including Melbourne.
"The murder was planned, the murder was targeted, and those responsible were likely guns for hire for other people involved," he said on Friday.
"There was a level of pre-planning ... in the days leading up to the murder there were things put in place to prepare for it."
Investigators on Friday released CCTV and images of two men and a white Volkswagen SUV they believe are involved in the shooting.
Det Supt Hatt said it was "highly likely" that the men pictured had carried out the shooting, although it's unclear who they are or who hired them.
Mr Boursinos had been approached by the unknown men in the laneway about 9am before he was shot several times.
Crime scene images showed a silver BMW sedan with its window shattered and door open with the man's body lying beside it.
Police said the offenders fled in waiting stolen Nissan Patrol and also used a stolen grey Volkswagen Golf, both of which were later found burnt out in Reservoir and Mickleham, respectively.
Detectives believe the men then got into a waiting silver BMW sedan.
Det Supt Hatt said the shooting was targeted, and the victim's connections to organised crime had added a greater level of complexity to the investigation.
"If you believe you have any information relating to the men who may have travelled down from New South Wales to carry out this murder, now is the time to speak up," he said.
