A person is in a critical condition after a truck and a car collided on State Highway 1 at Huntly.

Waikato police Senior Sergeant Pete Simpson confirmed there had been a serious crash between the two vehicles.

He couldn't confirm any other details of the incident but said SH1 around Fisher Rd, north of the town, is being closed and diversions are currently being put in place.

The Herald understands one of the occupants is in a critical condition.