A major route to a holiday hotspot remains closed after huge cracks were found in the passing lanes.

An image shows large fissures across lanes on the main highway linking western and eastern Coromandel.

Geotechnical assessments are being carried out on SH25A, motorists are being advised to use State Highway 25 as a detour.

Severe cracks have emerged on Kopu-Hikuai Highway prompting the road closure. Photo / Waka Kotahi NZ Transport Agency

The Thames-Coromandel District Council said a slip was “imminent” and the road, SH25a between Kōpu and Hikuai, is currently not safe to drive on due to the cracks close to the top of the summit from the Kōpu side.

Waka Kotahi NZTA said the next available update on the road will come at 8am tomorrow, however, the Thames-Coromandel District Council said it is unlikely the road will be open until midday.

Three people have been critically injured after a two-car crash on SH25A in the Thames-Coromandel District. Photo / Google

Motorists are being encouraged to use alternative routes such as via SH2 Waihi or SH25 Whangapoua Hill