It is believed the 35-year-old was walking on the Western Freeway near the Mount Cottrell Road entrance in Cobblebank about 7am when he was struck by a car turning on the highway.

Detective Senior Sergeant Paul Lineham said the man’s injuries were consistent with a hit and run.

“The consistency of the injuries would be that it wasn’t at high speed,” Lineham said.

“Given it’s a merging lane, it could be the case the driver didn’t actually know they struck someone.”

The man was taken to hospital with head, upper body and lower limb injuries.

A crime scene has been established while police investigate.

Anyone who was driving in the area between 2.30am and 7am has been asked to contact police or Crime Stoppers on 1800 333 000.