Five people have survived a helicopter crash in the central North Island this afternoon.
The Civil Aviation Authority said the crash happened just before 9am, 35km northeast of Waiouru.
The helicopter was undertaking a commercial survey operation in the area, the Rescue Coordination Centre said.
It said one person was in a critical condition, two were in a serious condition and two others had suffered less serious injuries.
The centre's search and rescue mission coordinator Dave Wilson said it received an alert from an emergency beacon on board the commercial helicopter at 8.50am.
Another helicopter from the same company was initially sent to the scene, with the Greenlea Rescue Helicopter from Taupō arriving soon after to provide medical care, he said.
"Distress beacons can summon life-saving help to people who need it and get them to hospital faster. In this particular case, the alert from the distress beacon was the only notification that the aircraft had crashed," he said in a statement.
A Defence spokesperson confirmed the chopper was not from the nearby Defence Force base.
The helicopter was carrying out a commercial survey operation.
The Transport Accident Investigation Commission will be investigating the cause of the crash.
Three investigators will attend the scene tomorrow.