Representatives of Anglo-Dutch oil giant Shell are appearing in a Dutch civil court to face accusations of polluting Nigerian villages.
The case is being brought by four Nigerian farmers and the Dutch branch of campaigners Friends of the Earth.
If their case is successful it could pave the way for thousands of other compensation claims, says the BBC's Anna Holligan in The Hague.
Shell insists it has been unable to clean up the spills due to insecurity.
The Anglo-Dutch firm also says that more than half of the leaks in the Niger Delta region are caused by theft and sabotage.
It is the first time a Dutch multinational has been taken to a civil court in the Netherlands in connection with damage caused abroad.
The case is linked to spills in Goi, Ogoniland; Oruma in Bayelsa State and a third in Ikot Ada Udo, Akwa Ibom State.
Channa Samkalden, lawyer for the Nigerians, told the court that Shell had failed to maintain its pipelines, clean up leaks and prevent pollution.
"Shell knew for a long time that the pipeline was damaged but didn't do anything. They could have stopped the leaks," she said.
The farmers say that spills from the oil firm's pipelines have destroyed their livelihoods by damaging crops and fish-farms.
