The case is one of a series of legal battles Shell has been fighting in London courts against residents of Nigeria’s oil-producing Niger Delta.

On December 20, 2011, an estimated 40,000 barrels of crude oil leaked when a tanker was loaded at Shell’s Bonga oil field, 120km (75 miles) off the coast of Nigeria’s Niger Delta.

Shell disputed the allegations and said the Bonga spill was dispersed offshore and did not impact the shoreline.

But on Wednesday, the Supreme Court upheld rulings by two lower courts that found they had brought their case after the six-year legal expiry date.

A panel of five Supreme Court justices unanimously rejected the claimants’ argument that the ongoing consequences of the pollution represented a “continuing nuisance”.

According to the Reuters news agency, the court did not look at the evidence supporting either side’s assertions or make a ruling on the issue, as it only decided on the legal point of nuisance.

“The Supreme Court rejects the claimants’ submission. There was no continuing nuisance in this case,” said Justice Andrew Burrows, delivering the ruling.

“The leak was a one-off event or an isolated escape. The oil pipe was no longer leaking after six hours,” he said.

A group of 27,800 people and 457 communities living in the delta have been trying to sue Shell, saying the leftover oil slick polluted their lands and waterways, damaging farming, fishing, drinking water, mangrove forests and religious shrines.

The average life expectancy in the region is 41 years, 10 years lower than the national average.

UK courts have previously ruled against Shell in another case involving pollution in the Niger Delta.

In February 2021, the Supreme Court allowed a group from the Ogale and Bille communities to sue Shell over spills, and that case is currently through the High Court.

At that time, Shell said it was not responsible for most of those spills and claimed they were caused by illegal third-party interference.

“We believe litigation does little to address the real problem in the Niger Delta: oil spills due to crude oil theft, illegal reining and sabotage, with which SPDC [Shell’s Nigerian subsidiary] is constantly faced and which cause the most environmental damage,” a Shell spokesperson said.

In a separate case in 2015, Shell agreed to pay 55 million pounds ($70 million) to the delta’s Bodo community in compensation for two spills after a legal battle in London.