A Toyota Altezza in which two people, understood to be passengers, died came to a rest by a fence near a paddock while a Toyota four-wheel drive veered just off the road facing the other car.
The other four-wheel drive is believed to have been towing the fourth vehicle.
Police serious crash investigators, fire crews from Hikurangi, Hukerenui and Towai rushed to the scene and helped free two people trapped in a car.
All vehicles were extensively damaged and had to be towed away.
The serious crash unit was in attendance and road closures were in place.
Police said diversions were in place for southbound traffic at the SH1 and Hukerenui Rd intersection, going via Jordan Valley Rd, and for northbound traffic at the SH1 and Jordan Valley Rd intersection, going via Hukerenui Rd.
Traffic detours will remain in place until further notice and motorists are advised to use alternative routes.
