State Highway One near Mangaweka in the central North Island is closed following a truck crash and solvent spill.
Two trucks collided shortly before 2am on Sunday and the road is blocked in both directions.
Inspector Paul Jermy says a crane is needed to clear the wreckage. it is still to arrive.
He is unable to say when the road might reopen.
Motorists at the scene report major delays, but diversions are in place via State Highways Three, Four and 49.