Wicklow County Council has refused to allow its records of water tests taken in the vicinity of illegal dumps to be scrutinised by a group of doctors.
The refusal has been described as "totally unacceptable" by the Minister of State for Europe, Mr Dick Roche.
The Minister had previously suggested there was a link between polluted water supplies to housing estates in Blessington and the proximity of a large-scale illegal dump on lands belonging to Cement Roadstone.
The Irish Doctors' Environmental Association applied in April 2003 for the water test records under the Freedom of Information Act but were refused last July.
An appeal against that refusal lodged last August, was turned down by the council last March.
According to Dr Elizabeth Cullen, the doctors' association is concerned with the health implications of groundwater pollution in the dump area.
Last year Wicklow County Council had "boil notices" in place for much of the year in the Deerpark housing estate, which is close to where illegally dumped waste was found on Roadstone lands. The Deerpark homes receive their water from a local well, which has, according to the council, been contaminated by "bacterial decomposition".
Mr Roche yesterday insisted that "a lively correspondence is on file" between himself and the council over the pollution of the well. But he said the "council insisted the problem was with a pump. There were undertakings and explanations but the fact is that where you have dumped domestic waste you invariably have pollution of the watercourse and the groundwater. Once it gets into the groundwater you don't know where it can turn up."
Offering to support any appeal to the information commissioner for access to the records Mr Roche said there was "no excuse for not releasing the tests".
However in its refusal to release the records, the council told Dr Cullen: "The County can not allow release of information which would prejudice legal proceedings at this time."
