The Taoiseach has been asked to initiate an inquiry into the deaths of newborns and young infants at mother and baby homes.
The call comes after claims that the remains of almost 800 babies were buried in a mass grave next to a home for unmarried mothers in Tuam, Co Galway between 1925 and 1961.
The Tuam Mother and Baby Home was run by the Bons Secours nuns.
Co-founder of Adoption Rights Alliance Susan Lohan said as-yet unpublished amateur research into similar homes in Ireland and Britain has highlighted concerns that need to be investigated fully.
"The research suggests that the mortality rate in these homes was in excess of double the national average," she said.
"These were state-funded homes. Anybody who suggests the nuns were doing their best….They were NOT doing their best. They tendered for this business (and) wanted this business.
"They got a headage payment for every mother and child in their so-called care, which was greater at the time than the average industrial wage."
She added that any plan for a memorial at the Tuam home was "just not good enough".
"There has to be an investigation," she said.