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.

“The arrest today holds immense importance for various reasons, especially concerning its implications for organized crime in Victoria,” stated Assistant Commissioner Martin O’Brien.

“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 has been well-known that Keshtiar has deep ties with several organized crime groups, which undoubtedly made the investigation more complex,” he added.

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

“We continue to focus on identifying everyone linked to this incident and urge anyone with information to step forward,” O’Brien appealed.