A female motorcylist has suffered life-threatening injuries after a crash on the Monash Freeway in Mulgrave.
Police say three vehicles and the rider collided on the inbound lanes about 6.15am on Wednesday 19 June.
The rider, who is yet to be identified, was taken to hospital with life-threatening injuries, police say.
All drivers of the vehicles stopped at the scene.
The driver of a Nissan hatchback sustained minor injuries and was conveyed to hospital for treatment.
The driver of a Nissan Patrol, a 34-year-old Pakenham man, is currently assisting police with their enquiries.
Major Collision Investigation Unit detectives are on scene and investigating the circumstances surrounding the collision.
As of 9.30am, Monash Freeway remained closed inbound from Wellington Road.
Any information, CCTV or dashcam footage to Crime Stoppers on 1800 333 000 or crimestoppersvic.com.au