A man has had to be cut from his car by firefighters after a crash on State Highway 16 near Kumeu, west of Auckland, this morning, the Fire Service says.
The two-car crash happened before 6.30am.
The service said the driver of one car fled the scene and a man with serious injuries was trapped in the other car.
He has since been freed and was being treated by ambulance staff.
The New Zealand Transport Agency said north-bound traffic was being diverted around the crash, but south-bound traffic could still get through.
Drivers were being asked to avoid the area and expect long delays.