Its case seems, at first sight, clearcut. The licence to operate, BP says, "is granted to us by the Indonesian government which is internationally recognised as the sovereign government of Papua, including by the UK and the United Nations". That is true. But its truth arises from a grotesque injustice.
At the beginning of 1962 West Papua was being prepared for independence by its colonial ruler, the Netherlands. But in April of that year JF Kennedy wrote to the Dutch prime minister, warning him that if he did not give the country to Indonesia, "the entire free world position in Asia would be seriously damaged". The Indonesian government would "succumb to communism" if it were not appeased. Robert Komer, Kennedy's CIA adviser, was even more direct. "A pro-bloc, if not communist, Indonesia is an infinitely greater threat ... than Indo possession of a few thousand miles of cannibal land."

But it couldn't be done overtly. Kennedy proposed that the Indonesians be allowed control of West Papua for "a specified period", after which the Papuan people would be "granted the right of self-determination". An agreement was drawn up in New York, stating that the UN would supervise a referendum in which "all adult Papuans have the right to participate".

The problem, as the US ambassador to Indonesia observed, was that "85 to 90%" of the population was "in sympathy with the Free Papua cause". A free vote would produce a clear result in favour of independence. So the US told the UN that the result had to be rigged. As a letter from the US embassy to the state department in 1968 revealed, the order was obeyed. The UN's representative was "attempting to devise a formula ... which will result in affirmation of Indonesian sovereignty".

So instead of a referendum in which "all adult Papuans" participated, in 1969 the UN oversaw a rather different process: 1,022 men were selected by Indonesian soldiers, taught the words "I want Indonesia", then lined up at gunpoint. One man who refused to say his lines was shot. Others were threatened with being dropped out of helicopters. This rigorous democratic exercise resulted in a unanimous vote for Indonesian rule.

No one who has studied this transfer of sovereignty believes it was fair. Four years ago the former UN undersecretary-general CV Narasimhan confessed, "It was just a whitewash. The mood at the United Nations was to get rid of this problem as quickly as possible ... Nobody gave a thought to the fact that there were a million people there who had their fundamental human rights trampled." In a parliamentary answer in December last year, the British foreign office minister Baroness Symons agreed that "there were 1,000 hand-picked representatives and that they were largely coerced into declaring for inclusion in Indonesia". Like East Timor six years later, West Papua was, in effect, annexed.

BP has a legal right to obtain a licence from Indonesia to operate in West Papua. But it is hard to see how this translates into a moral right.

By working under Indonesian consent, BP is at risk of lending legitimacy to the occupying power's presence. This is dangerous moral ground. A recent report by academics at Yale Law School concludes that there is "a strong indication that the Indonesian government has committed genocide against the West Papuans". Human rights groups suggest that around 100,000 Papuans have been killed by Indonesia. The armed forces have bombed, napalmed and strafed tribal villages and tortured and murdered their people. The government has sought to wipe out Papuan culture through forced assimilation and mass immigration. The purpose of these schemes, according to a former governor of West Papua, was to "give birth to a new generation of people without curly hair, sowing the seeds for greater beauty". Indonesia's genocidal intent is undimmed. Today, villages in the Papuan highlands are still being burnt out by soldiers, and their people killed or forced to flee into the forest.

All this is overlooked by BP. There is a page on its website labelled "Context: Papua". It tells you about tree kangaroos and birds of paradise, but mentions only that "human rights abuses" took place under Suharto (who was deposed in 1998). Since then, it suggests, the Indonesian government has started granting autonomy to the Papuan people.

It has done no such thing. It has failed to implement the "special autonomy" laws it passed, and instead has divided the nation into three regions, controlled directly by Jakarta. When the Papuans tried to set up their own assembly - the Papuan presidium council - its chairman, Theys Eluay, was murdered by the army. The Indonesian government is currently flying in an extra 15,000 troops. In the last few weeks the repression has intensified.

The lack of autonomy causes a particular problem for BP, which has justified its scheme by claiming that "Papua" will benefit by obtaining a share of the revenue. But who is Papua? There is no legitimate government of the Papuan people through which it could be channelled. The "central, provincial and local governments" to which BP will be giving the money all answer to Jakarta. Indonesia sits close to the top of Transparency International's corruption list. In March the Indonesian army was accused by the head of the West Papua Baptist Church of stealing $267,000 of aid destined for West Papua. How confident can we be that the money from the gas project won't go the same way?

BP has sought not to become directly involved with the perpetrators of the genocide. Instead of hiring soldiers to guard its gas plant, it is training local people. But, as the Free West Papua Campaign (www.freewestpapua.org points out, the Indonesian army has a standard technique for gaining control of extractive industries. It creates an incident, often attacking its own soldiers or burning down a village or two, blames it on the rebels and then insists it must "secure the area" - and, of course, any revenue arising from the area. The army is already building up civilian militias close to the gas field. Some of them are controlled by Laskar Jihad, which is affiliated to al-Qaida.

But all this skirts around the major question: that of consent. BP has conducted consultations and discussions with local people. But there is no representative Papuan assembly with the power to decide whether or not the project should go ahead, and on what terms. BP derives its authority to act from an occupying power in the midst of an attempted genocide. How credible, then, are its claims that its hands are clean?