A woman has been killed when her car crashed into a trailer carrying a house south of Ashburton this morning.
The crash occurred on State Highway 1 at Winslow, between Tinwald and Hinds, at around 10.45am.
The woman was the sole occupant of the car, which was travelling north.
"Initial inquiries indicate the vehicle has driven directly into the house trailer. The driver died at the scene," police said.
"No further information about the deceased is available at this time."
The trailer was transporting a house southwards on SH1 and was accompanied by pilot vehicles at front and rear.
It had earlier caused significant traffic congestion in the centre of Ashburton.
An investigation into the circumstances of the crash has begun, Ashburton police said.
Officers are speaking to witnesses and have appealed for the driver of a green Subaru station wagon, seen driving south through the area just before the crash, to contact their nearest police station.
The police serious crash unit and commercial vehicle investigation unit are at the scene.
The state highway is closed at Winslow. Diversions are in place through Long Beach Road, Boundary Road and Lynford Road, and are expected to continue for several hours.