THE US Supreme Court has issued a u

THE US Supreme Court has issued a unanimous ruling that limits the country's jurisdiction, delivering a major blow to human rights activists and providing relief to Rio Tinto.

The court threw out a lawsuit brought by human rights plaintiffs against Royal Dutch Shell that claimed it had facilitated torture and executions in Nigeria.

The ruling scales back the 1789 Alien Tort Statute - which has been used increasingly often to hold corporations accountable in the US for alleged misdemeanours in other countries, usually in the developing world, over issues ranging from human rights to environmental depredation to labour abuses.

This new ruling would appear to limit - or end - a long-running campaign in US courts undertaken by a leading contingency fee practice against Rio Tinto over the civil war that followed the closure of its mine on Bougainville in Papua New Guinea, on May 15, 1989.

The US Supreme Court ruled on a case brought by a group of Nigerians against Shell, which they complained was complicit with the government there during the 1990s in abuses including torture.

The court followed its own ruling by ordering a lower court in San Francisco, as a consequence, to reconsider its ruling against Rio.

Peter Taylor, the chairman of Bougainville Copper and president of the Australia PNG Business council, said yesterday: "This is a good result for foreign investment in PNG if it means that business can be confident that it won't be sued in the US - particularly where there is no breach of PNG law, and no connection with the US."

The San Francisco court, the US Court of Appeals for the Ninth Circuit, had earlier decided that Rio would have to defend a lawsuit accusing it of a range of offences - including genocide - in Bougainville, which the company, like Shell in its case, contested.

The case was originally filed in 2000 as a class action by 20 Bougainvilleans led by Alexis Holyweek Sarei, now aged 79, a former district commissioner before independence, and twice premier of Bougainville province, as well as high commissioner to Britain.

Mr Sarei, a former Catholic priest, married an American former nun, Claire.

They lived for a time in California, where he said that he risked "grave harm" if he returned to Bougainville.

But today he is a member of the Bougainville parliament, which is strongly backing moves towards the eventual reopening of the copper and gold mine.

The case was launched on a contingency fee basis by Seattle-based Steve Berman, one of the most prominent class action lawyers in the US. He was assisted by Melbourne-based Slater & Gordon, for which Nick Styant-Browne was then a partner. He is now working as an attorney for Mr Berman's practice.

The action claimed that the mine "laid the groundwork for environmental disaster by improperly dumping waste rock and tailings and emitting chemical and air pollutants without regard for the villagers".

It said that Rio "provided helicopters for troop transport" for the PNG government forces, and that "approximately 15,000 Bougainvilleans died as a result of armed acts by PNG troops".

Mr Berman brought the case in San Francisco, he said, because "we don't think we can get a fair trial in PNG", and because courts in Australia and Britain, where Rio is domiciled, "do not recognise this kind of case".

Mekere Morauta, who was PNG prime minister when the class action was filed, said at the time that even if successful the case would not be enforceable within PNG itself because of a Compensation Act there.

Bougainvilleans are due to vote within the next few years on whether they wish to remain within PNG or to establish an independent state.

They are already claiming, under their semi-autonomous status, that revenues which would be payable to government under a reopened mine should stay in Bougainville and not be shared with the PNG government in Port Moresby.

US Supreme Court Chief Justice John Roberts, explaining the ruling on the Alien Tort Statute, said: "Even when claims touch and concern the territory of the US, they must do so with sufficient force to displace the presumption against extraterritorial application.

"Corporations are often present in many countries, and it would reach too far to say that mere corporate presence suffices."

But an exemption was carved out in the case of piracy, in which sovereignty was defined considerably more broadly.