Police have arrested a man over the fatal shooting of underworld figure Mohammed Keshtiar two years ago.

The 23-year-old man will be interviewed by police in the coming hours after he was arrested in Dandenong this afternoon.

The car slowed as it passed the two men, before a passenger fired a number of shots in their direction.

Keshtiar was struck a number of times before he collapsed to the ground.

His associate was uninjured and managed to escape the scene.

The car stopped and a passenger wearing dark clothing stepped out of the car, shooting Keshtiar again as he lay lifelessly on the ground.

Members of the public tried to assist Keshtiar before he was taken to hospital, where he later died from his injuries.

“Today’s arrest is incredibly significant for a number of reasons, in particular because of what it represents in terms of organised crime in Victoria,” Assistant Commissioner Martin O’Brien said.

“This was an incident that involved a confronting level of public violence which could have easily impacted innocent members of the public.

“For that reason alone, this investigation has remained the highest priority for Victoria Police over the past 20 months.

“It’s never been any secret that Keshtiar had significant connections to a number of organised crime groups, which certainly added complexity to the investigation.”

In September last year, police offered a $1 million reward for information related to the shooting, an offer that still stands.

“Our focus remains on identifying all those involved in this incident and we again appeal for anyone who does have information to come forward,” O’Brien said.