An Air Force helicopter will be used this morning to try retrieve a car that crashed into the Mohaka River, killing three Mongrel Mob members.

The car plunged 150 metres down a cliff near the Viaduct, leaving three Wairoa men dead and one injured.

There have been suggestions the blue car, with a dent in its bonnet, may have run the Mongrel Mob vehicle off the road.

State Highway Two around Mohaka will be closed until midday to allow the chopper to winch the car from the river.

Detective Senior Sergeant Brent Greville says they've found evidence at the scene that suggests a blue car may have been involved.

He says they're appealing for any sightings of the other vehicle.