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.
Any information, CCTV or dashcam footage to Crime Stoppers on 1800 333 000 or crimestoppersvic.com.au
* As of 9.30am, Monash Freeway remained closed inbound between EastLink and Wellington Road.
Delays were reportedly easing to 45 minutes on the freeway as well as surrounding roads including EastLink northbound, Wellington Road between Rowville and Mulgrave, the Princes Highway through Noble Park and Springvale, plus Gladstone, Police and Jacksons roads.
The ramps from EastLink to the Monash Freeway are closed in both directions. Motorists are advised to use the ramps at Wellington Road or the Princes Highway.
The northbound lanes of EastLink are congested from Cheltenham Road, with delays of up to 15 minutes. Springvale Road provides a good alternative, according to the Department of Transport.
Commuters from the South-East were advised to consider using trains on the Cranbourne and Pakenham lines.