The Irish government was told about secret vaccine trials at least six years ago but has refused to investigate them ever since.

Pharmaceutical giant GlaxoSmithKline -- the firm that was behind controversial vaccine trials on children in state care during the 1960s and 1970s -- handed over records relating to the tests to a child-abuse inquiry in 2004.

The revelations have piled pressure on the Republic's Health Minister Mary Harney to launch an independent probe into the contents of the documents.

The Irish Department of Health admitted last night that its officials have been "in discussions" with the Commission to Inquire into Child Abuse about what to do with the records.

While the documents only show that "other vaccine trials" took place, it is so far not known how many other people were involved, whether children in state care were used for the trials or what medicines were tested.

Victims, adoption groups and opposition parties are now demanding a full investigation into all the vaccine trials on children in state care.

GlaxoSmithKline declined to comment. Its silence has raised serious concerns about the nature of the medical tests.

Those concerns have deepened as the department has so far failed to answer questions on the issue.

This newspaper put a series of questions to Ms Harney's officials this week. No answers were forthcoming.

The questions included:

• How many vaccine trials in total were conducted?
• Were children in care used in the trials and what consent was given for this?
• What, if any, are the long-term medical effects of the trials on the victims?
• Why has the State refused to investigate the contents of the files?
• Why has the Department of Health still not made a decision on what to do with the documents, despite being aware of them for a number of years?
• As part of its work, the commission requested information on three confirmed trials carried out by The Wellcome Foundation, a company that later merged with other firms to create GlaxoSmithKline.

These trials involved 211 infants and babies and were carried out in mother and baby homes and children's residential homes across the country in order to test new vaccines.

It remains unclear whether the parents or guardians of the children involved had consented to the trials or whether the company had complied with Irish licensing legislation.

As well as these tests, details of further, previously unknown trials, were also handed over to the commission by GlaxoSmithKline. A brief -- and unreported -- paragraph in the commission's Third Interim Report, published in January 2004, confirmed the receipt of the additional documents.

"The documentation discovered by GlaxoSmithKline also disclosed a considerable amount of information in relation to other vaccine trials in the State," the report said.

It stated that no decision had been taken on whether the extra trials could be investigated. In the end, no such investigation took place.

In June 2006, Ms Harney instructed departmental officials to discuss with the commission what should be done with the documents.

A spokeswoman for the commission confirmed that no decision was ever made.

The commission is not at liberty to release the files publicly without the approval of the department.

Adoption agencies last night led calls for an independent inquiry into the vaccine trials.

Susan Lohan, co-founder of the Adoption Rights Alliance, said: "I'm flabbergasted that the State and the adoption authority didn't know the extent to which vaccine trials were being used in this country.

"I am calling on the Government to ask the commission to hand over this new evidence to an independent inquiry, where it can be investigated immediately and authoritatively."

Fine Gael children's spokesman Charlie Flanagan said: "The Government needs to direct the commission to hand over this new evidence to be examined by the Oireachtas Health Committee.

"Then, based on the outcome of this, a national investigation needs to be held in order to gauge the extent of the vaccine scandal."

A spokeswoman for the commission said last night that it was prevented from investigating the vaccine trials on foot of two court cases taken by the doctors involved in the tests.

The vaccine module of the commission was closed down by Health Minister Mary Harney in 2006 on foot of that legal action.

Ms Harney said the issue of the vaccine trials was no longer a matter for the commission, which issued a report last year and is no longer investigating abuse claims.

She refused to comment on the calls for an independent inquiry or for the referral of the documents to the Oireachtas Health Committee.