Australian mining giant BHP Billiton and the operators of the Ok Tedi copper mine in Papua New Guinea are being sued for civil damages exceeding $US4 billion ($A5.08 billion) by villagers on the Ok Tedi River... [Plaintiffs' lawyer Carmellus] Narokobi represents six Ningerum clans who are not signatory to the Community Mine Continuation Agreement between landowners and Ok Tedi Mining Limited (OTML) [agreed following an earlier lawsuit in Australia]. [OTML is jointly owned by Inmet Mining, Govt of Papua New Guinea & PNG Sustainable Development Program]