A Fonterra tanker collided with a train at a level crossing near Gore early this morning.
The police said the collision happened at 1am on State Highway 1, closing the road.
St John Ambulance said a person was taken to hospital in Invercargill with moderate injuries.
Kiwirail said both drivers were injured in in the crash, and that both the locomotive and the truck are damaged.
They will be removed from the scene later today.
The highway was closed for three hours but is now open again.