A car travelling north on the Murray Valley Highway at Reedy Creek, near the New South Wales border, hit an object on the road just before 2.30am.
The driver stopped and found the body of a yet-to-be-identified man on the road.
The driver, who was uninjured, is helping police with their enquiries.
The investigation is ongoing.
The Murray Valley Highway will remain closed between Kerang and Lake Charm until further notice.