Latrobe Highway Patrol officers are appealing for a witness to come forward after a fatal motorcycle collision in Mirboo North this morning.
(UPDATE: Police have now identified and spoken to the witness and are no longer seeking his identity.)
Police are also investigating a motorcycle crash that claimed the life of a man in Buckland this afternoon.
In the first incident, police believed a motorcycle was travelling north-east on the Strzelecki Highway when it collided with the rear of a red Mitsubishi sedan waiting to turn into Darlimurla Road about 10.50am.
The driver of the Mitsubishi was not injured and stopped to assist at the scene.
It is believed the motorcycle then collided with a white Toyota 4WD which was travelling in the opposite direction.
The female driver and her male passenger were not injured and also assisted at the scene.
The male rider, who is yet to be formally identified, died at the scene.
Police are investigating the circumstances surrounding the collision and are hoping to speak to a man who stopped at the scene and was driving a white 4WD northbound on Strzelecki Highway.
The Strzelecki Highway was expected to remain closed between Mirboo North and Thorpdale for some time.
Anyone who witnessed the collision or who has dash cam footage is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au
In the second of the rider fatalities, police say the motorcycle was travelling along Buckland Valley Road when the rider left the road and crashed into an embankment about 1pm.
The rider, who is yet to be formally identified, died at the scene.
Anyone with dash-cam footage is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au.
Our sincere condolences to the families and loved ones of the deceased riders.