PAPUA New Guinea's Prime Minister, Sir Michael Somare, has accused Australian mining giant Rio Tinto and its subsidiary Bougainville Copper Limited (BCL) of being behind the PNG military's bloody suppression of Bougainville rebels opposed to the company's Panguna copper mine.

An affidavit written by Sir Michael when he was Opposition Leader in 2001 - and never made public - alleges that Rio played an active role in military operations that ultimately led to a civil war and blockade of the island in which 15,000 people died between 1989 and 1997.

"The government of PNG followed Rio Tinto's instructions" - Sir Michael Somare. Credit:AFP

''Because of Rio Tinto's financial influence in PNG, the company controlled the government,'' Mr Somare's affidavit states.

''The government of PNG followed Rio Tinto's instructions and carried out its requests … BCL was directly involved in the military operations on Bougainville, and it played an active role. BCL supplied helicopters, which were used as gunships, the pilots, troop transportation, fuel and troop barracks.''