One person has died, and three others have been seriously injured in a crash on the South Island’s West Coast.

A police spokesperson said emergency services were called to the two car crash on State Highway 7, in Arnold Valley just after 6pm.

It’s understood the vehicles crashed head-on.

NZTA said the road is still closed near Arnold River Bridge, while the Serious Crash Unit investigates.

A detour via Atarau Rd is available.