The Secretary General of the Department of Finance says he hopes to complete an internal review of the €3.6bn accounting error by the end of the month.
On Tuesday, the Department confirmed that a payment between State agencies had been counted twice.
Kevin Cardiff told the Dáil Public Accounts Committee that the report would be completed by the line managers concerned and would include a quality assurance check.
Mr Cardiff confirmed that no formal action was taken when the matter arose first and said it would form part of the review.
Committee Chairman John McGuinness and Fianna Fáil's Sean Fleming said they were concerned that the matter was not raised by the NTMA at the committee two weeks ago.
Mr Cardiff denied that he had deliberately withheld any information.
In response to questions from Independent TD Shane Ross, Mr Cardidd said it was 'a disappointment' that the error did not get higher than middle management.
Mr Ross said it wasn't a disappointment, it was a disaster. He asked would it have to be €100bn before Mr Cardiff might know about it.
The Public Accounts Committee is examining the error in a special sitting today.
Earlier, Mr McGuinness called on the Minister for Finance to correct the record concerning a statement he made regarding the €3.6bn accounting error in the national debt calculation by the Department of Finance.
Mr McGuinness said Michael Noonan had said publicly that the accounts had been signed off by the Comptroller and Auditor General, however Mr McGuinness said the C&AG does not sign off on the accounts, which were examined by Eurostat.
Speaking in the Dáil, Sinn Féin’s Mary Lou MacDonald asked the Tanáiste whether he still had confidence in the work of the National Treasury Management Agency.
Eamon Gilmore said the NTMA recently drew the attention of the Department of Finance and the Central Statistics Office to the error and said this kind of accountancy mistake was 'unacceptable' and all safeguards would be in place to ensure that it would not happen again.
