A large oil or diesel spill on State Highway One in Northland has caused a car to spin off the road.
Police are at the scene of the spill but don't yet know how extensive it is, police northern communications spokesman Inspector Ian Brooker said.
The spill, caused by either diesel or oil, is over the Brynderwyns in Northland.
Heavy vehicles are having difficulty with traction, while the spill caused one driver to lose control, and drive off the edge of the road, near Baldrock Rd.
Police would work with NZTA to control the situation, by placing signage in the area and laying sand over the spill, Brooker said.
Meanwhile, drivers were advised to be careful while in the area.