MAJOR Collision Investigation Unit detectives are investigating a fatal collision in Mortlake on Thursday afternoon.

Emergency services were called to reports that a silver Toyota Hilux utility and a grey Holden Barina had collided at the intersection of Castle Carey and Mortlake-Ararat roads at about 4pm.

The driver of the Holden, a 32-year-old Warrnambool man, died at the scene.

The driver of the Toyota, a 26-year-old Penshurst man, sustained serious injuries and was taken to hospital.

The exact circumstances surrounding the collision are yet to be determined and investigations remain ongoing.

Anyone who witnessed the collision, has CCTV, dashcam footage or any other information is urged to contact Crime Stoppers or submit a confidential report online at crimestoppersvic.com.au