More than 13,000 people from two communities in Nigeria have filed individual claims against the oil company Shell at the High Court in London.
Residents from the Ogale and Bille communities in the Niger Delta want Shell to clean up oil spills and compensate them for the damage to their land.
The claims, which were filed on Friday, are the latest development in a seven-year legal battle.
A spokesperson for the Shell Petroleum Development Company of Nigeria (SPDC) told the BBC that the majority of spills referred to in the Ogale and Bille claims were caused by third-party interference, including pipeline sabotage, illegal bunkering and other forms of oil theft.
Abimbola Essien-Nelson added that the illegal refining of stolen crude oil also happened on a large scale in these areas and was a major source of oil pollution.
Regardless of the cause, she said: “SPDC has and will continue to clean up and remediate areas affected by spills from its facilities or pipeline network.”
But the British law firm representing the communities says that no clean-up has taken place and that there have been 55 new oil spills in the Ogale community since September 2011.
A press release from the Leigh Day firm states Shell has filed a legal defence claiming that the communities do not have the legal right to enforce a clean-up against Shell.
Both communities are in Ogoniland, one of the most polluted regions in the world.
Despite a 2011 UN report recommending that the area be cleaned up immediately, residents still don’t have access to clean water and farmland.
In 2021 Shell announced it was leaving Nigeria and selling its onshore assets in the country after operating in the country for 80 years.
Shell has reported record annual profits after energy prices surged last year following Russia’s invasion of Ukraine. It made $39.9bn (£32.2bn) in 2022, the highest in its 115-year history.