A large slip has closed Waimana Gorge on State Highway 2 between Awakeri and Ōpōtiki.
NZ Transport Agency said the gorge will remain closed until a full geotechnical assessment is able to be completed.
The gorge is closed between Stanley Rd and Fraser Rd.
The road was initially only down to one lane but has since closed completely. NZTA said the slip material was unlikely to be cleared within the three hours initially estimated.
Motorists are advised to allow extra time for a detour via Ōhope and Whakatāne however this detour route is not suitable for HPMV vehicles.
Heavy vehicles are advised to park up and await the reopening of the road or detour via Taupō.