Two people have been hurt - one seriously - in a crash on State Highway 1 between Mosgiel and Allanton, south of Dunedin.

The two-vehicle crash occurred about 6.45pm on Tuesday.

The highway was closed, a police spokeswoman said.

She said the crash occurred between Riverside Rd and Law Rd.

A Hato Hone St John spokesman said one person had serious injuries and another had moderate injuries, and they had been taken to Dunedin Hospital.

Fire appliances were sent to the scene from the Mosgiel and Lookout Point stations.

They had since been stood down, a Fire and Emergency NZ spokeswoman said.