UPDATE 1.30pm: Police have confirmed the man killed in a road crash near Maldon this morning was a 24-year-old man from the town.
Onlookers tried in vain to save the man after his car hit a tree beside the Castlemaine-Maldon Road, near the Sandy Creek Road intersection, about 8.50am.
The car was heading in the direction of the Maldon.
Evidence at the scene suggested the driver had veered across to the wrong side of the road and hit the tree.
"At this stage driver error or fatigue is a possibility," Leading Senior Constable Brad Gutterson from the Macedon Ranges Highway Patrol said.
"The Major Collision Investigation group will inspect the vehicle... there's still a lot of steps to be taken from this point."
Ambulance Victoria spokesman John Mullen said the first witnesses to the scene had carried out CPR on the young driver.
"He was trapped in the car," he said.
"Onlookers continued to do CPR until paramedics arrived," he said.
Mr Mullen said paramedics continued CPR.
He said the male died at the scene.
Police, State Emergency Services, Country Fire Authority crews attended the crash site.
Police said the Castlemaine-Maldon Road would be closed for sometime as investigations into the crash continued.