More than 630 people who say they were abused as a child have not been allocated a social worker by Tusla.
The term 'retrospective abuse' refers to abuse that an adult experienced as a child.
According to new figures from Tusla, which relate to September 2019, there are 1,541 of these cases open at present.
While just over 900 of them have been allocated a social worker, 638 have not.
Data released by Tusla also shows that more than 5,100 children who are living in the community and have been referred to the child and family agency have not been allocated a social worker.
634 of these are deemed high priority cases, with nearly a third - or 192 - in Dublin South Central.
A further 472 children in state care have not been allocated a social worker.
Anne Rabbitte, Fianna Fáil's spokesperson for children, said she has "huge concerns" about the situation.
She said: "There could be children being abused at this moment, as we speak.
"All the while, the case of an adult who has been brave enough to come forward to disclose that they were the victim... and we have other victims being abused without any addressing of the matter.
"I believe when history will be written, it won't be kind to how we have dealt with priority cases and retrospective cases."
