Friends of Ali Duyar, who was shot in a Keysborough house on Wednesday night, have vowed to avenge his death, as police search for three other men who were with him at the meeting.

One of the men is believed to be the owner of a black Mercedes-Benz sedan that was parked in the front yard of the house on Thursday.

The man has posted photos on social media of guns and knives, including an image of him wearing a mask and pointing what appears to be a pistol down the lens.

Mr Duyar, 34, had been living in Doncaster, but it is believed his family had owned the Bloomfield Road house where the meeting had taken place.

Mr Duyar had been at the house with another man, believed to be the owner of the Mercedes-Benz, when two men arrived in a white Jeep about 4pm on Wednesday.

He was shot about 5.35pm and collapsed on the road outside shortly afterwards. Another man also left the house via the front door and was seen running south, and the two men from the Jeep are believed to have jumped the back fence and fled into Frederick Wachter Reserve.

Mr Duyar died in The Alfred hospital early Thursday from a single gunshot wound to the upper body.

It is unclear whether any of the three men were injured, but detectives believe only one shot was fired.

Homicide squad Detective Sergeant Stephen Sheehan said all four men were believed to have known each other. He would not say whether any drugs were found inside the house, or what type of gun had been fired.

The white Jeep was seized by police and is being forensically tested. It had not been listed as stolen.

"There was obviously some sort of meeting that's turned hostile," Detective Sergeant Sheehan said. "For what reason, we don't know, we're investigating that."

Friends of Mr Duyar posted on social media that they were thinking of his wife and children, and promised retribution.

"Weak doggss will get it... Love u bro u will be missedd," one man posted. Another friend posted that Ali's smile would stay with them.

"Its a wicked world we live in these days. Filled with evil people. The more i think about it the angrier i get every hour that passes.

"Such a gentleman......a family man. You will be greatly missed "brother", like you called us all. Our thoughts are with your family. We're going to miss you cuz."

Mr Duyar had previously operated a building design and construction business.

He had tattoos dedicated to his daughters, who he described on Facebook as his "heartbeat" and "angels".

Detectives are searching for CCTV of the street, but a witness has provided a description of the men who are believed to have arrived in the Jeep and fled through the reserve after the shooting.

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One man was tall and wearing dark clothing, and the other was shorter and wearing a light coloured top with dark pants.

Detectives have been unable to access footage from a CCTV camera attached to a rear building at the house that could provide vision of the driveway.

Detective Sergeant Sheehan said it was too early to speculate on whether the killing was linked to another unsolved shooting at the nearby Parkmore shopping centre in January last year.

Anyone with information about the shooting is asked to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au.

With Marissa Calligeros