One person is in a serious condition after a two-vehicle crash just south of Dunedin closed the road.

A police spokeswoman said emergency services were called to Blackhead Rd at 2.40pm on Wednesday. 

The road was closed while emergency services were at the scene. 

A Hato Hone St John spokesman said four people were treated at the scene with one person in a serious condition taken by ambulance to Dunedin Hopsital. 

The other three people, who did not require transportation to hospital, were in moderate to minor condition.