Women living near a nuclear power station have a higher risk of developing breast cancer, according to a new report.
Bradwell Power Station in Essex closed last March
The study was commissioned by campaigners who live near Bradwell Power Station in Essex.
Two earlier studies commissioned by Essex Strategic Health Authority found no detectable increases in cancer rates around the plant on the River Blackwater and close to Maldon and Mersea.
But campaigners asked environmental consultants to see if radioactivity in silt from the estuary would increase cancer rates.
The Green Audit study compared the female population of Maldon and another Essex town Burnham-on-Crouch, which is on the River Crouch and away from Bradwell.
The study by Dr Chris Busby and Richard Bramhall found that woman were more than twice as likely to suffer from breast cancer in Maldon compared Burnham-on-Crouch.
Campaigners claim statistical techniques used by the health authority made figures in one report look better than they were.
Dr Paul Watson, medical director of the authority, said: "The former North Essex Health Authority commissioned the Small Area Health Statistics Unit to carry out a report into the levels of cancer around the power station in 2001.
"A second report using slightly different information collection mechanisms came to a similar conclusion to the first that there was no detectable increased risk of cancer in the vicinity of Bradwell Power Station.
"Both reports were and remain available to the public."
Dr Watson said results of an independent report looking into the health authority's report and that of Green Audit are shortly to be published.
He added: "And we are confident it will support our view."
Bradwell, one of the oldest nuclear power stations in the UK, shut down last March when it stopped generating electricity.