In a BBC Radio 4 documentary, Mark Tully, who reported from the scene of the Bhopal gas disaster two decades ago, examines new evidence about the safety lapses which contributed to it.
Mark Tully in the derelict control room with former worker, M L Verma
Twenty years ago, poisoned gas leaked from a pesticide plant run by Union Carbide in the city of Bhopal.
According to the most conservative estimate, almost 4,000 people were killed. Thousands more have died since and hundreds of thousands were permanently affected.
But Union Carbide Corporation, or UCC, the American multinational which was the majority shareholder in the Indian company, is still distancing itself from the tragedy.
On its website, UCC says: "The Bhopal plant was designed, built, and managed by Union Carbide India, using Indian consultants and workers."
UCC's campaign to see that the blame for the accident falls on Indians and the Indian company, not on them, started almost immediately after the disaster.
When I was in Bhopal reporting on the immediate aftermath, officials who had arrived from UCC were maintaining that the Indian company was not "a subsidiary," and that the plant was entirely the responsibility of that company.
However, researching for "Bhopal- An accident waiting to happen?", I saw documents which confirm that there was a close relationship between UCC and the Indian company.
I also met witnesses who said there was every likelihood that the corporation did know the Bhopal plant was not being run safely. From the start, UCC was very anxious to ensure it retained the majority of shares in Union Carbide India.
Safety officer resigned
In the project report, the Indian company went out of its way to assure UCC that the new investment required for the plant would still leave it with more than 50% of the shares.
Documents also make clear that the plant was designed in America by UCC and this was confirmed to me by a former senior safety officer at the plant.
There is a report from a safety team sent out from America to inspect the plant in 1982, and a telex which shows that the plant was still seeking approval from UCC for some technical modifications just a few months before the accident.
Documents also show that at the time of the accident, UCC was discussing closing the plant - which it is now so keen to claim it did not control - and disposing of the equipment.
Thousands of Indians around Bhopal are still at risk of poisoning
It also seems certain that UCC knew there were doubts about safety at the plant. The former senior safety officer told me he had resigned because he was not satisfied with the response to his complaints about the running of the plant.
The evidence of the close relationship between the Indian Company and UCC suggests that his resignation must have been reported to headquarters.
I met another another senior Bhopal engineer who had been transferred to UCC in America. He told me that when he revisited the plant, he found that safety standards had fallen so much he became convinced it should be closed down.
He passed his concerns on to his boss in the company's American headquarters.
In spite of this evidence - and a lot more - linking UCC to the plant, the corporation has never been held responsible for the accident.
Instead of a court deciding what damages it should pay, UCC was able to negotiate a settlement with the Indian government.
It is still refusing to face trial in the Indian court hearing the criminal charges which have been brought against the company and its staff.
We would have liked to put these questions to Union Carbide, but they refused to give us an interview.
Abdul Mueen Khan's daughter Garzala, now 32, has become blind
They referred us instead to a statement on their website, in which they say the disaster was caused by sabotage - a claim which is disputed by several people we spoke to, including the police officer who supervised the criminal investigation.
In the 20 years since the accident the international community has not come up with any laws or regulations which would oblige UCC to stand trial.
One reason, according to the Canadian Law Professor Jamie Cassels, who has written a book on Bhopal, is "the unwillingness of the industrialised countries to forego the competitive advantages offered by the less developed world."
So the victims who died on that dreadful night in 1984, and the victims still suffering today from the gas, have not persuaded the industrialised countries, who boast so loudly about human rights, that the right to live safely is more important than profit.
There is still one rule for the rich and one for the poor.
Bhopal - An accident waiting to happen? was made by the File On 4 documentary team: BBC Radio 4, Monday 6 December at 2000 GMT.