Shell broke the law by not repairing leaks that destroyed the lands of Niger Delta farmers, a Dutch court heard Thursday in a case that could set a precedent for global environmental responsibility.

The four Nigerian farmers, backed by lobby group Friends of the Earth, have brought the Anglo-Dutch oil giant into court thousands of miles away from their homes with a civil suit that could open the door for hundreds of similar cases.

"Shell knew for a long time that the pipeline was damaged but didn't do anything: they could have stopped the leaks," lawyer Channa Samkalden told the court, accusing Shell of having "violated its legal obligations".

The case relates to damage caused in 2005 and was initially filed in 2008, demanding that Royal Dutch Shell clean up the mess, repair and maintain defective pipelines to prevent further damage and pay out compensation.

In a landmark ruling, the Dutch judiciary in 2009 declared itself competent to try the case despite protests from Shell that its Nigerian subsidiary was solely legally responsible for any damage.

"I'm here because of the oil leakage that happened in my community in the Shell facilities and destroyed my 47 fish pounds"," Friday Alfred Akpan, from the village of Ikot Ada Udo, told AFP before heading into court.

"The destruction of the fish pounds caused serious damage to me in person and my family because I make use of that fish to take care of myself and my children."

Oil pollution has ravaged swathes of the Niger Delta in the world's eighth largest oil producer, which exports more than two million barrels a day.

Shell is the biggest producer in the west African country, where it has been drilling for over 50 years.

Jonathan Verschuuren, an environmental law expert at the Netherlands' Tilburg University, said that a win for the farmers would set a precedent.

"If they win the case then it will be an important step that multinationals can more easily be made answerable for the damage they do in developing countries," Verschuuren told AFP.

"Until now it's been very tricky because it's difficult to bring cases against these companies in developing countries themselves, because the legislation is often not advanced or properly applied," he said.

Environmental groups accuse Shell of double standards and treating spills in Nigeria differently from pollution in Europe or North America.

"The scale of the pollution is enormous: twice as much oil has been spilled in Nigeria than was in the Gulf of Mexico. Only there (Nigeria) it's never been cleaned up," Friends of the Earth Netherlands spokesman Geert Ritsema told AFP.

The 2010 explosion and sinking of BP's Deepwater Horizon rig led to around five million barrels of oil leaking into the Gulf of Mexico in the biggest ever marine spill.

Shell, which is to address the court later on Thursday, says that spills in Nigeria are well below five million barrels and that the company cleans up whenever there is a leak, many of which it says are caused by sabotage.

Environmentalists want the Netherlands, and other Western nations, to pass laws forcing companies to enforce the same environmental responsibility standards abroad as at home.

Shell operates in over 90 countries, according to its website.