Amnesty International and Friends of the Earth Tuesday said they had filed an official complaint against Ango-Dutch firm Shell for shirking responsibility for oil spills in Nigeria and wreaking havoc on the environment.

A joint statement said Shell's operations in the southern oil-rich Niger Delta breached the Organisation for Economic Cooperation and Development (OECD)'s guidelines for responsible business.

"The organisations claim that Shell's use of discredited and misleading information to blame the majority of oil pollution on saboteurs in its Niger Delta operations has breached the OECD guidelines for multi-national enterprises," it said.

They filed the complaint with the British and Dutch government contact points for the OECD, the statement said.

Shell's operations in Nigeria spanning more than 50 years have "left an appalling legacy of environmental harm," it said.

"Water that people use for fishing and drinking is polluted with oil, while farm land and crops have been destroyed."

Shell will on Wednesday be under scrutiny for its environmental and human rights impacts during a hearing in the Dutch parliament on the company's activities in Nigeria, the statement added.

Nigeria, the eight largest oil exporter, recorded at least 3,000 oil spills between 2006 and June last year, Environment Minister John Odey has said.

The oil giant, which in the mid-1990s accepted causing much of the oil pollution in the Niger Delta, now "blames sabotage by communities and criminals", the statement said.

Under Nigerian law, compensations are not paid on damages caused by sabotage, it said.

The organisations accused Shell of "citing misleading figures that purport to show as much as 98 percent of oil spills being caused by sabotage."

"Shell's figures are totally lacking in credibility", said Audrey Gaughran, Amnesty's director of global issues.

"Widespread oil pollution is a key problem caused by oil industry in the Niger Delta, but the oil spill investigation system is totally lacking in independence," Gaughran said.

Shell said in a reaction that it "has reported oil spill data since 1996. Every oil spill is independently assessed by a joint inspection team comprising SPDC (Shell), the DPR (Department of Petroleum Resources)...and community members who agree on the cause and the volume of the spill."

The director of Friends of the Earth Nigeria, Nnimmo Bassey, said: "We monitor spills regularly and our observations often contradict information produced by Shell."

"Several studies have placed the bulk of the blame for oil spills in the Niger Delta on the doorsteps of the oil companies, particularly Shell," said Bassey, who also chairs of Friends of the Earth International.