Officers were called to the on-ramp of the Monash Freeway at the Eastlink interchange in Dandenong North at around 9:30 am on Thursday, following reports of an armed man in the emergency lane.

Upon arrival, they tried to negotiate with the 53-year-old Narre Warren man and calm him down before he produced a knife and advanced on them.

The officers fired a non-lethal beanbag round to try to stop the man before shooting him twice in the chest with a semiautomatic firearm.

Victoria Police Assistant Commissioner Robert Hill told reporters officers initially attempted to reason with the “distressed” man, who had parked his vehicle in the emergency lane of the freeway, but in the end officers were forced to discharge a firearm.

“We tried to negotiate with the male. We tried to actually calm the male down,” he said.

“At a point during that course of negotiation, that male has produced a knife and advanced on police members.

“Our police attempted a tactical withdrawal.”

“The male continued the advance.

“There was then a nonlethal force used upon the male to stop him from advancing.

“Then police resulted to lethal force.

“A semi-auto firearm was then discharged.”

Asst Comm. Hill described the shooting as a “tragic and sad” incident.

“At this point in time, there is nothing to indicate to me that our police members did not do everything they could to resolve the matter,” he said.

“Our members that are involved in this to a certain extent will be scarred by the scenario where through their actions someone lost their life.

“None of us come to work and want to be involved in these situations.

“It is a sad occasion for the family, loved ones and friends of the deceased male.

“It is a sad occasion for the community of Victoria.”

Multiple police vehicles and paramedics swarmed the scene, with the section of the freeway taped off.

Five police officers from the Critical Incident Response Team were involved in the initial exchange, with one injured after falling to the ground.

 Another seven officers rushed to the scene at its conclusion.

The man was known to police, but the motivations behind his erratic behaviour on the side of the freeway remain unclear.

However it is understood the man was suffering from a mental health episode.

Asst Comm. Hill confirmed officers activated their body cameras, with VicRoads cameras also capturing the events of the shooting.

He added that that homicide squad detectives, under the oversight of the Professional Standards Command, would investigate the shooting.

The officers involved will undergo blood and alcohol tests.

“We are still trying to understand why, what’s motivated, what’s triggered this situation,” Asst Comm. Hill said.