The man, who is yet to be formally identified, was discovered when he was hit by a car on the Murray Valley Highway at Reedy Creek, near the New South Wales border just before 2.30am.
A 59-year-old Nyah West woman driving the car stopped and called emergency services
Investigators believe the man may have been hit by another vehicle earlier, which left the scene without stopping.
Police said it may be possible he was hit by a large vehicle whose driver was not aware what had happened.
Detectives are trying to piece together the victim’s movements before his death and are keen to speak to anyone travelling in the area between 2am and 2.30am.
