A helicopter has crashed into the sea in French Pass about 5.20pm.

Witnesses reported seeing the helicopter collide with a power line which runs between D'Urville Island and the mainland.

The severed power line has been isolated.

Vessels in the area assisted with the search and divers have located the helicopter in about 10m of water.

The registration of the helicopter has been confirmed and it is believed there is one person deceased in the wreckage.

No further information on the identity of the craft or the person believed to be inside can be released at this stage.

The Police Launch and Police Dive Squad are being deployed from Wellington to recover the body.

This is likely to be completed today.

The CAA is investigating and the Coroner has been notified.

Source: New Zealand Police.