How many more clusters will have to be discovered before this government recognises that its existing models do not address the environmental causes of cancer

Euro MP, Michael Holmes

The report's author radiation expert and Green Party spokesman Dr Chris Busby, claims to have found that children there are 11 times more likely to develop myeloid leukaemia than the national average.

The town is five miles from Oldbury nuclear power station on the banks of the river Severn, which campaigners claim has been found to contain high levels of radioactive particles.

Myeloid leukaemia is a very rare form of cancer which is strongly associated with radiation.

The study - which used data from the Wales Cancer Registry - shows that three cases of the cancer were discovered in children up to the age of four between 1974 and 1990 in Chepstow, compared to the national average of 0.27.

Alan Howarth backs calls by Michael Holmes

It also reveals that children in Chepstow run a higher risk of developing all cancers at 3.54 times the national average.

Campaigners believe that the findings are comparable with the Sellafield leukaemia cluster which was highlighted in the 1990s.

Mr Holmes, who commissioned Dr Busby's report, said: "It is imperative that Health Minister Alan Milburn releases data on all cancer incidence down to ward levels as a matter of grave public concern.

"How many more clusters will have to be discovered before this government recognises that its existing models do not address the environmental causes of cancer?

Report dismissed

"It's possible the authorities know this is a much bigger threat then they are letting the public know - that's why they don't let the figures out."

Dr Busby applied for similar information to be released from the South Western Cancer Registry to find out if the incidence of cancer is as high on the English side of the river Severn.

But, he claims, he was refused access to the information on the grounds of patient confidentiality.

"This discovery begs for the immediate release of data for the English side of the river to give the complete picture, especially as Bristol is only eight miles from Oldbury and could be blighted," he said.

It is reported that British Nuclear Fuels - BNFL, which runs the Oldbury power station - has dismissed the report's findings.