The interim Garda commissioner said the force is investigating claims that the IRA moved alleged sex abusers across the border into the Republic.
Noirin O'Sullivan's comments come as the Dáil prepares to debate the Republican movement's handling of sexual abuse allegations.
Gerry Adams is expected to come under further fire from other leaders, who believe he and Sinn Féin are hiding information about the movement of abusers.
Sinn Fein TD Padraig MacLochlainn defended Adams earlier today, highlighting how he had cooperated with the investigation into his own brother, Liam Adams.
"If something like this happened in my family over a long period, it's extremely complex, extremely difficult - but what is face Gerry Adams understood that these allegations were reported to the RUC and the social services back in the 1980s."
"They were reported, and he gave evidence against his own brother."
Meanwhile, it has emerged that two men made Pearse McGeough, a lifelong republican and now Sinn Féin councillor in Co Louth, aware of allegations of sexual abuse that they allegedly suffered at the hands of an IRA member when they were minors.
The Gardaí were not informed at the time, and it is alleged that the abuser was then subjected to a "kangaroo court".
The incident allegedly occurred in County Louth, in an IRA safehouse.