Major Collision Investigation Unit detectives are investigating after a fatal collision in Nhill on 23 January.
It's believed a truck was travelling on the Western Highway just after 6pm when a male performing traffic control duties for road works in the area was struck.
The man, who is yet to be formally identified, has died at the scene.
The truck driver was not injured and remained at the scene.
The exact circumstances surrounding the collision are yet to be determined at this stage.
Motorists are advised that incident is expected to cause significant delays with sections of the highway closed while investigators process the scene.
Anyone who witnessed the crash or who may have passed through the area with dashcam is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au.
