Three people have been killed in a crash between a car and a tanker truck on State Highway 1 overnight.

Police said the crash happened around 11.50pm, about 5km north of Waiōuru.

All three people in the car died, while the truck driver suffered moderate injuries.

The Desert Rd has been closed between Rangipo and Waiōuru for more than seven hours, with detours in place.

Whanganui Area Commander Inspector Neil Forlong said the loss of three lives was heartbreaking.

“Our initial inquiries show the car has likely crossed the centre line just before the crash, but why that occurred is a focus of our investigation.”

A helicopter was sent to help search the area as there were initial fears that a fourth person had been in the vehicle, but that had been ruled out.

Forlong acknowledged the fast response from emergency crews “who faced a tough scene”.

“Crashes like this are devastating for the families involved, and the community and police will continue to support those affected by this tragedy.”

The Serious Crash Unit has completed a scene examination and the road is expected to reopen this morning.

A Fire and Emergency spokesman confirmed the service had attended the crash but referred queries to police.

A detour is in place between Waiōuru and Rangipo, the NZ Transport Agency website says.

Northbound drivers are being sent down SH49, before turning right onto SH4, right onto SH47, right onto SH46 and left back onto SH1, with southbound drivers following the same detour in reverse.