Police have visited the London and Amsterdam offices of Trafigura Beheer in connection with the dumping of toxic oil waste which killed 10 people in the Ivory Coast.

The Dutch oil company, which trades Nigerian oil for the Petroleum Corporation of Jamaica, has been at the centre of controversy locally since it was revealed it made a political donation of $31 million to the governing People's National Party (PNP). Prime Minister Portia Simpson Miller, the president of the PNP, has since ordered her party to return the money.

The oil waste was dumped at 17 mostly open-air sites in the Ivory Coast, which made thousands ill.

British lawyer Martin Day has started court proceedings against Trafigura to compensate relatives of the victims and for those made ill. He is reportedly claiming £100 million.

Ivorian company blamed

Trafigura, which estimates that its 2006 turnover will come to $45 billion, denies wrong-doing and blames an Ivorian company for not disposing of the waste properly.

Trafigura, which acknowledged the visits by police last week, said it was cooperating with the investigation by Amsterdam Environmental Police.

Meanwhile in the Ivory Coast, an investigation is under way to find out how the waste was discarded after it was unloaded from the Panamanian-registered tanker.

The company's director and West Africa regional director have been detained in Abidjan and face charges under Ivorian toxic waste and poisoning laws.