Bogus non-resident accounts held at AIB Finance comprised nearly 40 per cent of AIB's £90 million (€114.27 million) DIRT bill, according to the Revenue Commissioner's report presented to the Dail Committee of Public Accounts this week.

In all, the Revenue collected more than £170 million from the audits.

The report, seen by The Irish Times, shows that AIB Finance's role in DIRT evasion accounted for £34.6 million of the bank's DIRT settlement with the Revenue. Its audit, which covered the period between 1986 and 1999, established that AIB Finance had an underlying DIRT liability of £14.5 million. On this amount, the Revenue applied interest of £19.9 million and penalties of £196,000. The bulk of AIB's settlement related to accounts held throughout its branch network and together with interest and penalties came to £55.4 million.

The report gives details of all sums recovered from the 37 financial institutions audited by the Revenue, which amounted to £173.3 million. This included unpaid tax of £70.5 million, interest of £99.7 million and penalties of £3 million.

All of the audits have been completed with the exception of IIB Bank and Guinness and Mahon (Ireland), which are subject to wider Ansbacher investigations. Both banks have made payments on account ahead of any full settlement and this is included in the final figure. The report also discloses a payment of £4.6 million from GE Capital Woodchester Bank. This includes tax of £1.9 million, interest of £2.4 million and penalties of £259,000. Irish Nationwide Building Society paid £4.4 million, of which £2.2 million was tax and £1.9 million was interest. A further £292,000 was applied in penalties by the Revenue.

The report is being studied by the Dail Committee of Public Accounts and brings the DIRT Inquiry to its final stages. A hearing will be held at the end of the month with the committee expected to question Revenue Commissioners chairman Mr Dermot Quigley on further details of the various settlements. Other key figures are likely to be called to answer questions.

The report gives a broad explanation of the sampling processes used in arriving at these tax demands but does not disclose details of individual negotiations with each of the institutions. During the audit, the Revenue also examined documents relating to Special Savings Accounts opened for customers at the various financial institutions to ensure they were being operated within the legal framework. Overall, the Revenue stated that it was satisfied these terms were being met.

During the audits, which were carried out by more than 60 Revenue officials, samples of accounts, instructions made to staff about opening and operating these accounts, internal audit reports and other sources of information were considered.