A man and woman are dead after the car they were travelling in lost control and crashed into an oncoming campervan in northern Waikato yesterday.

The crash happened on a notorious stretch of State Highway 2 in Mangatawhiri, often referred to as the "highway of death", about 1.20pm.

The couple are the third and fourth people to die on the highway this year, following a fatal crash just last month and one in January.

A gold-coloured sedan was left contorted in a ditch on the wrong side of the road after it collided with a Britz rental van. Both the front and back windscreens were smashed and the car's panels and undercarriage were badly damaged.

"The preliminary indications at the moment are two vehicles travelling in opposite directions on SH2, one vehicle has lost control and collided with the other," police Senior Sergeant Myles Horsnell said.

Both occupants of the car – a man and woman – were killed.

The two occupants of the campervan were uninjured despite the bonnet being crumpled, causing the driver's airbag to open.

They were at the scene being questioned by police. A man who was travelling in the campervan declined to speak with the Times last night. "I don't want to talk about it," he said.

Mr Horsnell said the crash was yet another tragedy on the infamous highway.

Thirteen people died, and 22 suffered serious injuries, on the highway between 2005 and 2010 and the speed limit was lowered to 90kmh at the end of last year to improve safety.

"Whatever the circumstances are it's a tragic event and a sobering thought for the weekend traffic.

"Hopefully it's the last one."

Diversions were in place around the crash scene for about four hours yesterday afternoon, causing delays for some motorists.

Mr Horsnell said the victims' names would be released once their family has been notified.

The police Serious Crash Unit is investigating the cause of the crash.

- © Fairfax NZ News