An Ivory Coast court jailed a Nigerian man for 20 years for the 2006 dumping of hundreds of tons of toxic waste from an international oil trader that killed at least 16 people and left more than 100,000 needing treatment.

Salomon Ugborugbo, 39, owned a local company whose trucks collected the eye-stinging waste offloaded from the Dutch-based company’s ship and dumped it at 17 sites in the capital Abidjan including close to homes forcing thousands to flee.

The main spot was a huge garbage dump that French clean-up crews could only approach with gas-masks.

Ugborugbo was convicted and sentenced late Wednesday. An Ivorian shipping agent, Essouoin Koua Desire, who played a key role in Ugborugbo’s local company Tommy securing the US$20,000 waste disposal contract, was also convicted and jailed for five years.

Five customs officials, the Abidjan port’s military commander and its maritime director were acquitted.

An official government investigation named Ugborugbo as the “principal” actor behind the tragedy but defense lawyer Charles Mentennon criticized the decision not to put officials from Dutch-based Trafigura on trial. Many Ivorians blame Trafigura for the tragedy.

Trafigura paid the Ivorian government US$197 million last year in part to help clean up the waste but maintains it was not liable for the incident.

Soon after the payment, three Trafigura officials were freed from prison, but Trafigura says they were only released because under Ivorian law they could not be held six months without being charged.

Critics allege Trafigura hired Tommy to save money. The ship had previously stopped in the Netherlands where officials would have charged 16 times more for the work.

Government investigators say Tommy was set up solely for the dumping operation and did not have the technical ability to do so properly.

Trafigura maintains the waste was not toxic, but was a mix of gasoline residues, water and caustic sodas used for cleaning. U.N. experts, however, say the waste contained hydrogen sulfide, which in concentrated doses can kill humans.

Defense lawyer Charles Kignima called verdict against Ugborugbo “unjust.”