Rights group Amnesty International has termed investigations by corporate giant Shell into oil spills in Nigeria a "fiasco", alleging that the company repeatedly blamed sabotage in an effort to avoid responsibility.

"No matter what evidence is presented to Shell about oil spills, they constantly hide behind the 'sabotage' excuse and dodge their responsibility for massive pollution that is due to their failure to properly maintain their infrastructure," Audrey Gaughran, director of global issues at Amnesty, said in a recent statement.

She said that "the investigation process into oil spills in the Niger Delta is a fiasco," referring to the oil-producing region that is home to Africa's largest crude industry.

In 2008, a spill caused by a fault in a Shell pipeline caused tens of thousands of barrels of crude oil to spill out into the Nigerian delta.

Four years on, the oil still floats on the waters of Bodo Creek. Local rights and environmental groups say that it is killing and contaminating plants and wildlife in one of Africa's most bio-diverse regions.

The case, filed by 11,000 Bodo residents against the Anglo-Dutch oil giant, is currently being heard in a London court.

Shell has admitted liability in the 2008 disaster in Bodo, although there remain significant disagreements over the amount of oil that poured into the creeks.

Claims of the amount spilled have ranged from 1,640 barrels to more than 60 times that amount.

Al Jazeera's Mohammed Adow reports from Bodo, Nigeria.

Source: Al Jazeera