The Child and Family Agency, Tusla, says it has completed an audit of social work files in Laois-Offaly following the discovery of hundreds of previously unidentified files earlier this month.
Tusla said there are a total of 743 case files.
Of these 660 require the allocation of a social worker, including 127 requiring immediate attention.
Tusla says that all referrals, some of which date back to 1998, had received some level of attention, but the standard file management procedures had not been followed.
The agency said file-management procedures were being reviewed and improved.
Tusla says it has begun to recruit additional staff so that the current staff complement can deal with referrals while the backlog receives urgent attention.
Tusla Chief Operating Officer Fred McBride said efforts would be ongoing to strengthen IT capacity, not just in Laois-Offaly but throughout the organisation.