Newstalk has reported that experimental drug trials were conducted on at least 290 children across 10 mother-and-baby homes in the 1960s and 70s.
The trials were said to be conducted at homes at Bessborough in Cork, St Peters in Westmeath, St Clare's in Stamullen, The Good Shepard in Dunboyne as well as six Dublin Homes.
In one of the trials, 80 children allegedly became unwell after they were given a vaccine intended for cattle in a trial at five care homes and orphanages in Dublin in the mid 70s.
The information is contained in a report from the Chief Medical Officer of the Department of Health's report to the Oireachtas in the year 2000, obtained by Newstalk.
Susan Lohan, co-founder of the Adoption Rights Alliance, says that any claims that the parents of the children gave permission for the trials to take place are "not credible".
“The mothers of the children were not consulted on anything regarding their childrens’ welfare,” she said.
“I find it, frankly, nor credible, that the managers of those places would have made an exception when it came to the vaccine trials.”
The news comes as the Government decides what powers and scope a potential inquiry into the homes could have.