Australia's biggest gold producer Newcrest Mining Ltd (ASX: NCM) has reported that nine of its staff were killed in a helicopter incident in Indonesia on Wednesday.

In a disclosure to the Australian Stock Exchange, Newcrest said the two Australia residents working for its project in joint venture with Indonesian state firm PT Aneka Tambang perished in the accident that also killed five Indonesian residents and two South Africans. There is one Indonesian survivor, who is still in critical condition.

The helicopter was flying from Manado on Sulawesi Island to the Gosowong Mine on Halmahera Island when it crashed near Manado, the company said. The cause of the crash, which occurred about 2:30 p.m. local time yesterday, is not yet known, it said.