One person has died and another has been injured in two-vehicle crash on State Highway 1 north of Kaikōura.

A car and truck collided just before 6am on SH1 at Hapuku.

The second person suffered minor injuries and was treated at the scene.

Police want to hear from anyone who may have witnessed the crash.

"We are particularly interested in speaking to the occupants of a white van, which was seen in the area at the time and may be able to assist us with our enquiries," a police spokesperson said.

Motorists should continue to avoid the area, as the road remains blocked.

We ask that drivers please remain patient, as we work to have the road cleared as soon as possible.

SH1 is closed, between Seaward Valley Rd and Kiwa Rd, and expected to be for several hours.

Motorists are being asked to delay travel or avoid the area.

There are no diversions available.

Location of the accident scene at Hapuku north of Kaikōura. Photo / Google Maps

Southbound traffic travelling from Picton to Christchurch have been advised to detour via SH6 from Blenheim SH63, SH6. SH65, SH7 and SH1 at Waipara.

Police say anyone who witnessed the crash, or has any information which could assist Police, is asked to please contact 105, quoting event number P052047473.