The burial site at the Tuam Mother and Baby Home in Co Galway may have been much bigger than previously thought.
More than 700 children died at the home between 1925 and 1961.
Evidence uncovered by local historian Catherine Corless, and presented to the Children's Minister James Reilly, points to a far more extensive burial site.
She is due to speak on the issue at a conference at NUI Galway this evening.
Meanwhile, the draft terms of reference for the Commission of Inquiry into the matter has been circulated to all of the relevant departments.
Minister Reilly has told Tipp FM that witnesses will be compelled to appear before the inquiry - which is being chaired by Justice Yvonne Murphy.
He said: "The issue of additional burial areas has been raised with me and the commission will look into all of this.
"I would like to assure people that this commission is set up under the Commissions Act and therefore Judge Yvonne Murphy and the commission will have the power to compel witnesses."