Six of the 10 crew were members of the elite Special Air Service Regiment (SAS), defence officials said.

The helicopter was operating off the HMAS Kanimbla warship, which was sent to the region earlier this month amid heightened tensions in Fiji.

The helicopter crashed into the sea as it tried to land on the Kanimbla.

Defence Air Chief Marshal Angus Houston said nine of the 10 crew on board were rescued, although one later died from his injuries.

Seven had suffered light injuries and were being treated on board the Kanimbla, he said.

Ships in the area are "continuing to search the area for the missing person,'' he added, giving no further details about the dead or missing soldiers.

The Kanimbla is one of three naval warships sent by Australia to be ready to evacuate citizens if fears of a coup in Fiji are realised.