One woman is dead and four people are injured following a crash on State Highway 1 on Sunday.
Police say it appears a car crossed the centre line just north of Ashburton at about 2.30pm, pushing one vehicle off the road and colliding with another car head on.
A woman in her forties died at the scene and four people were taken to Christchurch hospital.
Two of them are in critical condition, and the other two have minor injuries.
State Highway 1 has been reopened to all traffic.