A crash involving a truck and a car near Methven has killed two people and left one with serious injuries, police say.

The two killed were in the car, while the truck driver has serious injuries and has been airlifted by helicopter to hospital.

The Serious Crash Unit has been advised and an investigation into the circumstances of the crash is underway.

The road remains blocked and diversions are in place.

The collision happened around 11.55am on State Highway 77 Waimarama Rd at the intersection with SH72, near Methven, a police spokeswoman said earlier.

Emergency services - including fire and ambulance - also attended the accident.

Police this morning said two occupants of the car and the sole occupant of the truck had all suffered serious injuries.