Oil trading firm Trafigura agreed to pay 33 million euros (49 million dollars) after caustic soda and petroleum residues were dumped in Abidjan.
In August 2006, the Probo Koala ship, chartered by Trafigura, dumped the dangerous material on waste tips across the city -- having first attempted to offload the cargo in Amsterdam.
An out-of-court settlement agreed in London on September 20 awarded 750,000 CFA francs (1,150 euros, 2,200 dollars) to each of the 31,000 victims.
The money was to be distributed by the victims' British lawyers Leigh Day and Company, but Claude Gohourou, the president of the Ivorian national coordination of toxic waste victims, told AFP he obtained a court order last month blocking payment.
Gohourou called for Leigh Day and Company to prove it was for them to hand out the compensation, and criticised the firm for allowing details of the settlement to remain confidential.
Kouame Klemet, a lawyer with the British firm in Abidjan, pointed out that Trafigura had required the settlement to remain confidential and gave assurances that it was indeed the firm's job to pay the money to the victims.
An Ivorian court recently ruled the victims' group case to be inadmissible, but upheld the blocking order, saying the law firm had not shown it was properly mandated to make the payments.
Both sides have appealed and a decision is expected in the coming weeks.
Compensation has so far reached only a handful of those affected in the indicent, according to Klemet.
Trafigura has already paid one hundred billion CFA francs (152 million euros, 225 million dollars) in damages to the victims in an out-of-court deal with the Ivory Coast government, which exempted it from legal proceedings in that country.
A report by a UN expert found "strong" evidence linking the waste to 15 deaths and several hospitalisations.
But Trafigura has always disputed this and its position was upheld in the London out-of-court settlement, which ended legal proceedings against Trafigura in Britain.
The agreement accepted there was no link between exposure to the waste and any deaths or miscarriages, as was alleged.