A court in the Ivory Coast has ruled that compensation due to thousands of victims of dumped waste should not be paid to one man to distribute.
Oil trading company Trafigura had agreed to pay $45m (£27m) to 30,000 victims in an out-of-court settlement.
Claude Gohourou argued he should be given responsibility for the money, but there were doubts he would pass it on.
However, despite the ruling the money remains blocked and victims cannot yet gain access to their compensation.
Trafigura had agreed to pay people who said they had been made ill by waste dumped from the ship.
The money is in addition to the nearly $200m that the company paid the Ivorian government in 2007.
In September, Trafigura and the plaintiffs' lawyers agreed that a link between the dumped waste and deaths had not been proved.
A joint statement by the company and the British lawyers representing the Ivorians, Leigh Day and Co, said at worst the waste had caused flu-like symptoms.
The compensation had been paid by the company into two holding accounts at a bank in Abidjan but in October a court stopped the solicitors from distributing the money - following representations by Mr Gohourou.
The BBC's John James in Abidjan said the latest court session was held behind closed doors.
It declared its verdict after an hour, saying that Mr Gohourou's organisation - the National Co-ordination of Toxic Waste victims - had no legal right to freeze the accounts because the association had only just been set up.
People danced, cheered and hugged each other as those who'd made it inside the court building gave their verdict, our correspondent said.
Many of them were victims of the dumping and shouted: "No to Gohourou."
One woman told our correspondent: "We don't know Mr Gohourou - we thank God for us winning this case today."
He was one of around 100 community activists who originally helped to collect the names and documents of those claiming compensation.
In return the organisers would get 3% of any compensation payment made.
Martyn Day, senior partner at Leigh, Day & Co, the London solicitors representing the victims, said he was delighted with the ruling.
He told the BBC News website: "There are a couple of formal processes the court has asked us to do but we are hoping to move on with things next week".
However despite the ruling, the money has not been unblocked and the victims will not be receiving their money anytime soon, our correspondent says.
Both Leigh, Day and Co and Mr Gohourou will now have to prove their right to represent the victims before the money can be released.
This money is in addition to the nearly $200m (£120m) that the company paid the Ivorian government in 2007.
Trafigura is a privately owned Dutch firm with offices in London, Amsterdam and Geneva.
It recently failed in its attempts to stop a British newspaper, The Guardian, from publishing a scientific report into the dumping.
The report suggested the likely cause of illnesses suffered by thousands of Abidjan locals was the release of potentially lethal gas after chemicals were dumped.
Trafigura said the report was just a draft.