"This report represents complete vindication for Newmont and confirms that Newmont has told the truth, has mined responsibly and has properly managed the environment of Buyat Bay," Tom Enos, vice president of international operations and former vice president for Newmont's Indonesian operations, said.

The study showed that the water in Buyat Bay is not polluted, data on fish found that total mercury is below the standard prescribed by the WHO and was fit for human consumption.

Nevertheless, five Newmont employees remain in police custody in Indonesia in connection with an investigation over the pollution claims.

Last week, Newmont's Chief Executive Officer, Wayne Murdy, went to Indonesia to visit the men who have been held in jail since last month.

The police investigation is looking at whether Newmont employees dumped tailings at a level that exceeded permissible amounts. Newmont spokesman Doug Hock said the company continues to cooperate in the probe.