A motorcycle rider was fighting for life after a collision on the Monash Freeway on Saturday 19 July.
A car and a motorcycle collided near the Wellington Road exit at Wheelers Hill about 12.47pm, police say.
Officers say the rider was riding in tandem with another motorcycle at the time of the collision.
The second rider was not injured and has since been arrested by police.
He was expected to be interviewed in relation to the incident.
The male rider was taken to hospital with life-threatening injuries.
The male driver of the vehicle stopped at the scene.
Four inbound and four outbound lanes were closed that afternoon as Major Collision Investigation Unit detectives attended the scene.
Any CCTV/dashcam footage or other information to contact Crime Stoppers on 1800 333 000 or crimestoppers.vic.com.au
