The New England Highway is expected to be blocked for most of the day following a fatal crash south of Tenterfield this morning.

One person died and three people were injured when the car left the highway and struck a rocky embankment about 35km south of Tenterfield.

Highway Patrol officers from Tenterfield had initiated a pursuit of the vehicle a short time earlier when it failed to stop for a random breath test about 12.35am.

The officers had followed the vehicle for about 5km north before the crash occurred.

Police rendered assistance at the scene before ambulance personnel arrived.

A 17-year-old woman, who had climbed from the vehicle unassisted, was taken to Glen Innes Hospital with minor injuries.

Two men, ages unknown, have been taken by helicopter to Lismore Base Hospital and the Gold Coast Hospital with serious injuries.

The highway is completely blocked and will remain so until police from the Crash Investigation Unit have completed their examination of the scene.

Southbound traffic is being diverted at Glen Innes to the Pacific Highway at Grafton. There are no alternate routes available for heavy vehicles other than via Gunnedah and the Newell Highway. Motorists are urged to avoid the area if possible.

The vehicle carries Queensland number plates but records indicate the vehicle is currently unregistered.

A Critical Incident Investigation Team from Barwon Local Area Command has been appointed to examine the circumstances surrounding the crash.