One person has been killed and another is critically injured after a four car crash north of Dunedin.

St John communications centre manager Andy Gray said one person was dead, another critically injured and up to six had received minor or moderate injuries.

The crash happened near Hawkesbury Village, near Karitane, at 5.56 this evening, he said.

Traffic is backed up to the north and south of the crash near the intersection of Apes Rd and State Highway 1, about 30km north of Dunedin.

It appeared at least one car was down a bank.

Two helicopters were at the scene just before 6.30pm.

Motorists have been warned to expect delays of up to 25 minutes, and diversions are in place.

Police said, in a brief emailed statement, that they were currently attending the crash.

They could not provide details of how many people or vehicles were involved at present.

"More information will be supplied when it becomes available,'' the statement said.

Emergency services remain on site.