Police have arrested a man in Melbourne after a car mounted a kerb and crashed into pedestrians, killing one.

A grey Toyota struck two pedestrians on Langs Road in the Ascot Vale suburb just before 17:00 local time on Saturday, according to Victoria Police.

One pedestrian died at the scene, while the second was taken to hospital with life-threatening injuries.

The circumstances surrounding the collision are still being established, and the arrested man is expected to be interviewed shortly.

Local media reported that the incident occurred outside the Melbourne Showgrounds, where the Supanova Comic Con & Gaming event was ongoing over the weekend.

Images from the scene showed a police cordon surrounding the vehicle, which appeared to have sustained damage.

Detective Inspector Craig McEvoy mentioned that the driver was apprehended by an off-duty officer with public assistance.

Although it remains uncertain if the incident was intentional, authorities are investigating all possibilities, including the potential influence of drugs or alcohol.

Eyewitness Tom recounted, I heard a screech and a guy mounted the kerb at an erratic speed, hitting a couple of people. He further added that the driver attempted to flee before he intervened.

Thousands of attendees were expected at the venue, which is known as the 'home of Australia's pop culture fandom.' The event featured notable guests like Andy Serkis from 'The Lord of the Rings' and Bonnie Wright from 'Harry Potter.'