The Ferns inquiry, which is investigating how allegations of clerical child sex abuse were handled in the mainly Co Wexford diocese, is not now expected to submit its report to the Department of Health before the end of March.
The inquiry, which held its first hearing in September 2003, is dealing with three outstanding matters and is awaiting responses from third parties.
Following the resignation of Dr Brendan Comiskey as bishop of Ferns, George Bermingham SC was asked in 2002 by the then minister for health, Micheál Martin, to investigate which would be the best form of inquiry to look at how allegations of clerical abuse were dealt with in Ferns.
He also examined other claims related to the diocese, including allegations against the former president of St Patrick's College, Maynooth, Mgr Micheál Ledwith, a former priest of the diocese. His report was made available to the inquiry.
On Thursday the Dáil Public Accounts Committee is expected to publish its report on the €128 million indemnity deal agreed between the State and 18 religious congregations. It is believed the report will be critical of aspects of the deal.