A HIQA investigation has found that some children are being left at potential risk because of system failures at Tusla.
The health watchdog began investigating practices at the child and family agency after the Children's Minister ordered an inquiry in 2017 after Maurice McCabe was falsely accused of seriously abusing a child.
The report has now been published, and has found 'serious shortcomings' into how Tusla manages child sex abuse allegations.
A lack of social workers is mentioned as one area of concern, but HIQA says systems are also failing.
The report also found there was no formal process for Tusla to communicate with the gardaí - although there was excellent 'informal sharing' of information between the two agencies.
Launching the report, Mary Dunnion - a lead investigator with HIQA - explained: "By October 2017, the investigation team had identified - and escalated to the minister, the department and Tusla - that there was three key defective points.
"In essence it means there is an actual systems risk which places children at potential risk."
In the Dáil, Sinn Féin leader Mary Lou McDonald suggested that "as it stands, [Tusla] is not fit for purpose."
Responding to the investigation, Leo Varadkar acknowledged: "The report catalogues failures and enormous shortcomings in Tusla and in child protection.
"The problems that exist around child protection are well known - but they are being dealt with over time, and we will continue to deal with them."