The Government's Special Rapporteur on Child Protection was commissioned by the Government to investigate the issue.
Professor Conor O'Mahony's report is due to be published later today.
Last year, RTÉ investigates found thousands of babies were illegally adopted, by being registered at birth as the biological children of their adoptive parents.
Susan Lohan, Co-founder of the Adoption Rights Alliance, says a full investigation is needed:
"There should be a truth commission on all adoptions. And that's something that Adoption Rights called for when the dreadful commission of investigation into mother and baby homes was instigated, because we've never looked at the forced adoption industry in Ireland, and that's what we need. We need to start at the top. You know, we shouldn't just be pulling at little threads, we need to unravel the whole murky industry."
