A man has been injured after the car he was driving plunged 50 metres down a bank and into a river near Port Levy.

A police spokesman said emergency services were called to Port Levy-Pigeon Bay Road, between Pa Road and Little Pigeon Bay Road, about 2.20pm.

 A vehicle is reported to have left the road and crashed down a 50m bank into the river the spokesman said.

 It appears the sole occupant managed to extricate himself from the vehicle.

Fire and Emergency crews are at the scene.

A St John spokesman said an ambulance and a first response unit responded.

One patient was assessed at the scene and was transported to Christchurch Hospital in a moderate condition.