Mr Jim Mitchell, chairman of the Dail Committee of Public Accounts, has expressed disappointment with the settlement by AIB, the bank at the centre of the DIRT inquiry.

"Given that this sum is only little short of the bank's original estimate of £100 million, which gave rise to the DIRT inquiry in the first place, it seems incredible that the largest financial institution in the State would take such steps to force it to pay over 90 per cent of what it itself estimated it owed," said Mr Mitchell in a statement.

"It also belies the case made by AIB at every stage that it had settled with the Revenue Commissioners."

AIB's apology over DIRT evasion has been welcomed by Mr Pat Rabbitte, a member of the ail Committee of Public Accounts (PAC) PAC sub-committee, which investigated Irish financial institutions' compliance with the tax.

In a statement, Mr Rabbitte said: "I welcome the fact that the bank has settled, albeit belatedly, and see no point in second guessing the work of the Revenue Commissioners, who had the opportunity and resources to get to the amount due. We can only assume for the moment that the figure settled on is the actual amount due."

But Mr Rabbitte, Labour's enterprise, trade and employment spokesman, added that when the DIRT hearings resumed at the end of November, it would probe the detail of the settlement.

"For today, the bank's apology to the compliant taxpayer is long overdue," he said.

Mr Mitchell noted that the AIB settlement meant the Revenue had received more than £157 million in outstanding DIRT, penalties and interest as a result of the inquiry, which cost £1.8 million.

"Even these substantial yields do not fully take into account the dramatically improved cash-flow to the Revenue for DIRT on an ongoing basis as soon as the inquiry started," Mr Mitchell added.