Some 5,000 smear tests in seven hospitals are to be reviewed, the Minister for Health, Mr Cowen, told the Dail.

These included five hospitals where individuals worked who had screened smear tests for the private laboratory which incorrectly diagnosed tests carried out for the North Western Health Board in 1997.

A further 350 tests were being reviewed by Beaumont hospital and Our Lady of Lourdes Hospital in Drogheda, Co Louth, which had both used the private laboratory in 1997 for screening, and results were expected in the next week from these institutions.

Mr Cowen said the review of tests going back to 1994 was being carried out purely as a precaution and they were having "the absolute maximum investigation which is prudent in the circumstances".

The Minister also said he had asked Claymon Laboratories to provide a list of any private clients for whom it had carried out tests.

Some of the tests were screened by the individuals in their own homes.

Labour's health spokeswoman, Ms Liz McManus, said some of the testing appeared to have the hallmarks of a "cottage industry". She wanted to know if such "home" laboratories were still in existence and if they were acceptable to the Minister.

Fine Gael's spokesman, Mr Alan Shatter, said it was an "outrageous scandal" that home screening was carried out.

The Minister said he was unaware of any home testing apart from this case and if it was being carried on it was in breach of contract.

Answering a special notice question, Mr Cowen said they had identified all the personnel who had carried out the work for Claymon Laboratories.

"The Bon Secours Hospital in Cork has confirmed its involvement on behalf of Claymon Laboratories," he said. St Vincent's Hospital in Dublin did not carry out any work for the laboratory but work was done in a private capacity by staff from the hospital.

"Preliminary screening was not carried out at the hospital but at home," he said. "The staff concerned also had attachments with St Vincent's, Elm Park, Mount Carmel, St Michael's in Dun Laoghaire and the Bon Secours Hospital in Glasnevin."

Mr Cowen stressed he was not aware of any problems in these hospitals but to allay fears he had asked the hospitals to review the work carried out by these professionals and to let him have an early report on the situation. The review would cover 1994 to 1998 and about 5,000 tests.

Further attempts were made by The Irish Times to contact the chief executive of St Vincent's Hospital, Mr Nicholas Jermyn, for comment yesterday. However, for the second successive day, no response was forthcoming.