Two dead in Vic road tragedy

The drivers of two cars described to police as racing erratically and side-by-side on a Victorian highway before a fatal crash are aged in their 50s and 60s.

Victorian police say concerned witnesses called them about a high-speed car race on Saturday on the Calder Highway at Glenalbyn, near Bendigo, moments before two of three vehicles involved collided.

Emergency services were called to the crash about 12.40pm (AEDT).

Two of the vehicles, a blue Ford station wagon and a light brown Ford Falcon, crashed and ran off the road.

The station wagon struck a tree, killing two men inside the vehicle.

The 67-year-old male driver of the Falcon was taken to Bendigo Hospital in a serious condition.

His 35-year-old female passenger was airlifted to the Royal Melbourne Hospital in a serious condition.

Both have serious head injuries and remain in hospital under police guard.

The occupants of all three vehicles are known to each other, police say.

The driver of the third vehicle, a 51-year-old Wedderburn man, is in custody.

Police are investigating the circumstances leading up to the crash.

The highway remains closed while the crash scene is examined.