In an unprecedented joint operation on Friday, the French police, navy and Greenpeace took samples from around the discharge pipe of the Cap de la Hague reprocessing plant - France's Sellafield. The samples are being analysed.
This is the latest in a series of actions surrounding the plant, sited on the very tip of the Normandy peninsula close to the island of Alderney. The French government has already closed beaches around the plant and banned fishing and yachting.
Earlier this year a study by government scientists, investigating an abnormally high incidence of leukemia, suggested that children who visited nearby beaches or ate local fish were more likely to get the disease. If confirmed, the results of the study might help explain a leukemia cluster near Sellafield.
Until now Cap de la Hague's operations have been shrouded in secrecy, protected by a party political consensus backing one of the world's heaviest commitments to nuclear power, which provides three quarters of the country's electricity.
But, after his recent election, Prime Minister Lionel Jospin announced that the nuclear industry "cannot be exempted from the rules of democracy". He appointed Dominique Voynet, the leader of one of the country's green parties, environment minister. He has put the plant under unprecedented scrutiny.
This weekend's investigation had its origins in a freak low tide this spring, which uncovered the end of the plant's discharge pipe, revealing alarmingly high levels of radioactivity. In July, Greenpeace published the results of tests which it said showed that the waste being pumped vastly exceeded EU limits.
The group returned to the pipe last week with special permission from the environment ministry. It says it found a vast clean-up operation on the seabed suggesting that "Cogema [the company that runs the plant] is desperately trying to conceal pollution". Acting on its information a French investigating magistrate ordered divers to take Friday's samples.Reuse content