The Centre for Environment, Human Rights and Development (CEHRD) and Amnesty International state that Shell corrupts Nigerian authorities and intervenes in the process of oil spill investigations, and distorts them. All this leads respectively to wrong conclusions in most of the surveys.
In Nigeria, oil spills are pretty much a common event. There are hundreds of them, on an annual basis. The spills are ecological disasters. They damage the environment and endanger the live and the health of all people around.
To prove their doubts, the Centre for Environment,
Human Rights and Development (CEHRD) and Amnesty International hired the
private American agency, Accufacts, that is known for its expertise in
Accufacts examined some reports of the investigations conducted by Nigerian authorities. The agency concluded that the stated causes for the oil spills in the delta of Niger could be classified as "very subjective, misleading and downright false." Accufats also contacted other oil companies working in the region and the national oil spill agency of Nigeria, to be able to make a sounder analysis.
The agency encountered several cases in which sabotage was stated as reason for the spills and evidences were falsely interpreted. Sabotage was also pointed out to be the cause of oil spills in many cases in which simply there were too little or no evidences to support such a statement.
Accufacts classified the investigation reports of Nigerian authorities as "technically incomplete", or as "serving another agenda, more driven by politics" instead of genuine "pipeline forensic science".
Amnesty International in turn, also acknowledges that regulatory agencies in Nigeria lack resources to control and monitor the process and for the conduct of the investigations they have to rely on oil companies.
You can find the report of Amnesty International HERE