Shell has been accused of ignoring the rule of law in Nigeria, with one of the company's own former lawyers leading the legal fight.
Peter Roderick was a lawyer at Shell between 1985 and 1991 and is now the co-director of the Climate Justice Programme at environmental charity Friends of the Earth.
Friends of the Earth is trying to stop Shell using gas flaring in Nigeria to burn off unwanted by-products of oil production. Gas flaring can cause high rates of leukemia and asthma and can damage vegetation through acid rain.
In November 2005 the Federal High Court of Nigeria found gas flaring to be a human rights violation and ordered Shell to stop.
Shell appealed and obtained a stay to allow gas flaring until 30 April 2007. The deadline has passed and Roderick says Shell is still using flaring.
Roderick said: "I'm actually shocked this is happening, because a strong rule of law is essential for their own business."
Friends of the Earth is waiting for the hearing date of the appeal.