The Rescue Coordination Centre says it's not yet clear whether the beacon went off automatically, or if it was activated by the pilot before he died.
The Transport Accident Investigation Commission added Robinson helicopters to its watchlist in October, after 18 people died in 20 years in crashes caused by rotor blades hitting the masts.
Spokesperson Roger Foley says two investigators are on the way to Reefton to find out what went wrong.