Man dead in multi-vehicle smash on Princes Freeway

A man has died in a multi-vehicle smash on the Princes Freeway in Melbourne's west.

Major Collision Investigation Unit detectives are investigating after a number of vehicles crashed near Kororoit Creek Road at Laverton about 5.50am.

Police believe a Ford Ranger utility towing a trailer was travelling outbound in the far-left lane, when it collided with three other cars.

The collision caused a white Kia sedan to veer across the freeway, when two trucks collided with the vehicle.

The male driver of the Kia who is yet to be formally identified, died at the scene.

Paramedics assessed several people at the crash site, but no one was taken to hospital.

Footage captured by 9News shows a truck smashed into a car, with debris scattered across the road.

The Princes Freeway remains closed outbound at the M80 Ring Road. Heavy traffic is building on the Princes Freeway, M80 Ring Road and the Deer Park Bypass city-bound, with motorists urged to avoid the area.

Victoria Police were likely to have the area closed for some time.

Police Minister Lisa Neville in a press conference said the crash was very "serious" and traumatic for both the families and emergency workers involved.

"I pass on my thoughts to everyone involved," she said.

"It is going to cause a lot of trauma. These are the sorts of accidents that have significant scars for those workers."

The drivers involved in the smash were assisting police with their enquiries.

Police have appealed for witnesses or anyone with dash-cam footage to come forward.