Sellafield power station has been identified as the source of plutonium contamination across the UK.

Public health minister Melanie Johnson admitted in November that a government-funded study found that levels of the material in children's teeth were highest among those living near the plant.

"Analysis indicated that concentrations of plutonium...decreased with increasing distance from the west Cumbrian coast and its Sellafield nuclear fuel reprocessing plant ? suggesting this plant is a source of plutonium contamination in the wider population," she said.

The government has insisted that the findings suggest no danger to the public's health, due to the levels being so minute. However, ministers face calls for an independent public inquiry into the matter.

"This stinks of a cover-up," said Liberal Democrat environment spokesman Norman Baker. "They have known for six years that Sellafield has contaminated the population with plutonium but done nothing. Yet the plant continues to discharge plutonium into the Irish Sea. It shows the wanton disregard the nuclear industry has for public health and there needs to be an independent inquiry."

Owners of the plant, BNFL, have questioned the study's findings. "What is not clear is whether the plutonium recorded in this study originated from Sellafield or from nuclear weapons testing fall-out," said a spokesman.