UP TO €40m in unpaid tax may be swept up by the Revenue Commissioners after special investigations into offshore accounts.
Tax officials are on the trail of 1,133 cases in the Cayman Islands, Jersey, Switzerland and Liechtenstein where trusts and offshore structures may have been used to conceal funds.
A total of €20m has already been collected in voluntary disclosures and settlements from 100 cases after Revenue gave taxpayers who had undeclared funds an opportunity to make a voluntary disclosure by September 2009.
Preliminary investigations have revealed that most offshore trusts were facilitated by third parties such as fund managers, investment advisers and tax consultants.
Some of these funds were designed to create the impression that the non-resident trustees or entities are the owners of the funds, concealing the identities of the Irish beneficiaries.
Earlier this week, the Labour Party claimed that a significant number of the highest-income earners in Ireland are still paying little or no tax.
Labour's finance spokeswoman, Joan Burton, said that out of the 234 individuals earning between €250,000 and €500,000 per annum, a total of 54 paid a tax rate of between 0pc and 5pc while a further 34 paid tax rates of less than 10pc.
Revenue also said that it expects to collect millions of euro from special investigations into other sectors including income from "legacy investigations".
Bogus non-resident accounts investigations are expected to return €3m, single premium life insurance policies should provide €3m and undeclared offshore assets are estimated to be worth a further €3m.
The financial services unit at the Revenue Commissioners has also been keeping an eye on tax issues arising from the crisis in the banking sector which has so far yielded €28m last year in corporation tax, VAT and stamp duty.
The Revenue's 'high-wealth individuals' unit initiated inquiries into around 300 directors and senior executives in the banking sector which has already provided around €1m in tax settlements.
Last year, the State's overall tax take fell by some €7bn, while DIRT audits yielded around €225m, bogus non-resident and Ansbacher accounts resulted in €419m and €109m respectively.