Police and emergency services are currently on the scene of a fatal crash which occurred at Armstrong between Great Western and Ararat earlier this morning.
A passer-by contacted police after coming across the crash scene on the Western Highway just after 6.30am.
Investigators believe the east-bound vehicle crossed onto the wrong side of the road and crashed into a tree.
A man, thought to be a front-seat passenger, died at the scene.
Two other occupants from the vehicle, a woman and a teenage girl were airlifted to a Melbourne hospital with serious injuries.
Police are still to formally identify the people involved in the crash
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au