Campaigners say the State could be in breach of international law for its involvement in the Tuam Mother and Baby home.
The Irish Council for Civil Liberties says the crime of 'Enforced Disappearance' involves a state refusing to disclose the whereabouts of people who have been abducted.
It is thought hundreds of children were secretly buried on the Tuam site.
Thousands of children were also thought to have been illegally adopted through homes nationwide.
Liam Herrick from the ICCL says the State has important duties in the Tuam case.
Mr Herrick said: "This is not a question of the State having a choice in how it deals with these matters, there are matters of legal obligation.
"The obligations are that a full public investigation should take place, that the bodies should be identified, in so far as is possible, that the remains are returned to the families, in so far as is possible