A 32-year-old man is dead and another is in a critical condition after a helicopter crash near Lindis Pass, in Central Otago, a spokesperson for St John Ambulance says.
Police responded to an emergency beacon that was activated shortly before midday.
A Rescue Coordination Centre spokesman said a rescue helicopter and another chopper carrying a cliff rescue team arrived at the scene not long afterwards.
The survivor, a 51-year-old man, was flown to Dunedin in a helicopter with head and chest injuries.
The Rescue Coordination Centre spokesman said he believed the crashed helicopter was a Robinson R22.
The Transport Accident Investigation Commission has previously called attention to the high rate of accidents involving the Robinson R22.
The Civil Aviation Authority has been notified.