It has emerged that the Irish government was made aware of the secret vaccine trials at least six years ago but failed to investigate the issue.

GlaxoSmithkline is the firm responsible for the controversial vaccine trials on children in state care during the sixties and seventies in Ireland.

According to the Irish Independent the giant pharmaceutical firm handed over documents relating to the drug trials to a public child abuse inquiry in 2004.

Despite mounting pressure from the Irish media, the Department of Health has yet to reveal details of the drug trials. The Minister for Health, Mary Harney, is under severe pressure to order a full investigation into the trials.

The trials involved over 200 infants and babies and were carried out in adoption centers and children’s residential homes across Ireland. It remains unclear if parents or guardians consented to the trials or whether the pharmaceutical company had conformed to the Irish licensing legislation of that era.

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."

In recent weeks Mari Steed, a victim of the trials now living in Philadelphia, announced that she and three other victims are planning to separately sue the Catholic Religious order because of their facilitation of the trials.

Steed became aware of her involvement in the trial after she discovered her medical records while searching for her birth Mother. Her birth mother later confirmed that she had not given consent for the trials to be carried out on her baby daughter.