One person has died in a collision between a pedestrian and a motorcycle in Grovedale.
Emergency services were called to Reserve Road just after 10am.
The pedestrian, who has yet to be formally identified, passed away at the scene.
The 20-year-old motorcyclist from Tarneit was taken to hospital with non-life-threatening injuries under police guard.
Police are yet to determine the exact circumstances of the collision.
The road is expected to be closed for many hours, with motorists advised to avoid the area while investigators assess the scene.
Anyone with info is urged to contact Crime Stoppers on 1800 333 000 or at www.crimestoppersvic.com.au.