Credit: CTOC
A police spokesperson said the "serious crash" involved a car and a van.
It was reported on the Geraldine-Fairlie Highway, near Earl Rd, in Pleasant Valley about 8am.
Emergency services are currently at the scene.
The spokesperson said the section of State Highway 79 is closed and diversions are in place.
The Christchurch Transport Operations Centre said delays are possible.
Motorists are advised to avoid the area if possible.
