No representatives from the Dutch-based international oil trader, Trafigura, which had chartered the Panamanian-registered Probo Koala vessel that unloaded the waste in Abidjan, were accused in the trial that had opened late last month.
Trafigura had already agreed a nearly $200 million out-of-court compensation settlement with the Ivory Coast government which exempted it from legal proceedings in the West African country.
The company denies any responsibility for the deaths and illnesses suffered by Abidjan residents after the dumping.
Vincent T'sas, an independent journalist in the Ivory Coast, told Al Jazeera: "People are saying that the main culprits are not in court - the people of Trafigura - and they could have been because they have spent - right after this dumping - six months in prison here.
"One of the prisoners was the president of Trafigura, but after six months he was released because the company made a deal with the government saying OK, we will pay $200,000 million if you free us.
"That is what angers people. People are still suffering," he said.
|Exposure to noxious fumes has left many people needing treatment [AFP]
When the Abidjan trial opened, Trafigura said in a statement it would present independent experts to prove the waste could not have been responsible for their illness.
The petrochemical waste was described by Trafigura as "slops", residues from gasoline mixed with caustic washings.
Defence lawyers in the Abidjan hearings had repeatedly complained that it was unfair for their clients to be in the dock when executives from Trafigura were not on trial.
But the Dutch-based company faces a possible class-action suit next year in London courts brought by a British law firm representing thousands of Ivorian victims seeking tens of millions of dollars in compensation.
Many victims have already been compensated from the out-of-court settlement, but many say they have not received enough compensation.
At the height of the scandal in 2006, Abidjan hospitals were overwhelmed as thousands sought treatment for vomiting, nausea, diarrhoea and breathing difficulties after exposure to noxious fumes.
T'sas said on Thursday: "I went to a village near the dump today and I saw a woman who was covered in sores who has had them since the dumping in 2006.
"It's raining at the moment in Abidjan and the fumes of the toxic waste are still in place. Although there has been a clean-up operation, it has not been completlely cleaned."