State Highway 2 through the Waioeka Gorge is closed after an estimated 200 tonnes of earth has fallen onto the highway.

Waka Kotahi NZ Transport Agency says SH2 between Ōpōtiki and Gisborne has been closed since 3am following one large and two smaller slips in the Waioeka Gorge.

"It's estimated around 200 tonnes of earth has come down onto the road between Matawai and Ōpōtiki," says a spokesperson for the roading agency.

"Waka Kotahi contractors have been working to clear the road since first light.

"As this was the detour for SH35 – there is now no suitable detour."

State Highway 35 between Ōpōtiki and Te Kaha was closed earlier last night when the road collapsed along the centre line and the eastbound lane fell into the Motu river. Read more here.

Traffic had been reduced to a single lane due to the large crack in the road since Monday, July 18.