A stretch of road between Whangarei and Dargaville has been reduced to one lane, due to a slip

NZTA says a minor slip caused by last week's heavy rain has caused a crack in the road, on State Highway 14 at Tangiteroria.

The highway's been reduced to one lane while the crack is investigated.

Meanwhile, State Highway One through the Mangamuka Gorge in the Far North remains closed due to a number of slips.

Road crews have been clearing slips on the southern side.

However, several slips near the summit on the northern side are still moving.