State Highway 1 north of Balclutha remains closed this morning after a head-on collision in which a woman was killed and another seriously injured last night.
Police says it was rainy and wet when the vehicles collided at Stony Creek, 10km north of Balclutha, about 5.30pm.
A 32-year-old Southland woman, who had been driving a southbound Nissan Pulsar, died at the scene.
The driver of the other car, a 59-year-old South Otago woman, suffered serious injuries and was airlifted to Dunedin Hospital.
Police said SH1 was closed overnight for a scene examination to be carried out early this morning.
Diversions have been put in place at Station and Patterson roads until the highway reopens later this morning.
Investigators from Balclutha police and the serious crash unit are investigating the cause of the crash.
They are seeking witnesses travelling in that area who may have seen a dark grey Nissan Murano 4WD or a silver Nissan Pulsar.