Police are investigating after a man was located deceased on the Western Freeway on Tuesday night.
Police were called to the scene about 11.30pm and believe the man had been driving a car which was involved in a crash.
Investigators believe the 23-year-old Thornhill Park man exited his car and was struck by another vehicle which failed to stop at the scene.
The exact circumstances surrounding the incident are yet to be established.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au.