A man has been arrested after a car drove into a crowd outside a Melbourne comic convention, killing one pedestrian and leaving another fighting for life.

A young man has died and another person is fighting for life after a car drove into a small group outside a major Melbourne comic convention, with police declaring a major collision investigation and arresting a man at the scene.

The chaotic incident unfolded outside the popular Supanova Comic Con and Gaming event at the Melbourne Showgrounds on Saturday afternoon.

Emergency services were called just after 5pm, when thousands had gathered for the two-day celebration of cosplay, gaming and pop culture in Melbourne.

A pedestrian died at the scene and another person was taken to hospital with life-threatening injuries following the collision outside the Melbourne Showgrounds. Picture: NewsWire / Tony Gough
Detective Inspector Craig McEvoy said a grey Toyota Echo travelling along Langs Rd in Ascot Vale veered onto the wrong side of the road, mounted the kerb and then drove along the footpath, striking a group of three men in their 20s before crashing into a fence outside the Showgrounds.

It is understood the young men had attended the convention and were leaving the event at the time. One of the men died, another suffered life-threatening lower limb injuries, and the third was traumatised but physically unharmed.

Inspector McEvoy said the driver, a 33-year-old Werribee man, was “well known” to police.

“It’s extremely unusual that the car has travelled across an entire lane before getting up onto the footpath,” Inspector McEvoy said.

“The footpath is not in the same direction as he was travelling … so to get across the lane, up onto the footpath and then travel 120 metres along the footpath in between a 2-metre-high fence, trees and power poles, is extremely rare.”

Victoria Police have confirmed a man has been arrested and will be interviewed by detectives. Picture: NewsWire / Tony Gough
After the impact, a witness said he approached the driver, who he described as behaving aggressively. He said he was able to restrain the man and prevent him from leaving before police arrived.

He also said his wife, a paramedic, immediately assisted one of the seriously injured victims, working on them for about 20 minutes before emergency crews took over.

“The driver was then arrested by an off-duty police officer, who was assisted by some members of the public,” Inspector McEvoy said.

“That driver has now been conveyed to hospital, he’s under police guard and we’ll investigate accordingly.”

Emergency services were called to the corner of Langs Rd and Epsom Rd just after 5pm on Saturday. Picture: NewsWire / Tony Gough
The witness said attendees were quickly moved away from Gate 2, the main entry point for exhibitors, as police secured the area in Ascot Vale.

He described seeing a badly damaged blue-grey sedan on the curb, with police tape cordoning off sections of the site while officers and security worked to clear crowds.

A heavy emergency presence remained at the scene into the evening.

The incident occurred outside the Supanova Comic Con and Gaming event, which was hosting thousands of attendees. Picture: Facebook/ Nathan Black
Supanova Comic Con and Gaming has run since 2000 and is one of Australia’s largest pop-culture conventions, bringing together fans of comics, sci-fi, fantasy, anime, gaming and film.

The event typically features celebrity guests, exhibitors and cosplay, while also providing a platform for artists and creators to showcase their work.