It is thought that the accounts in question are deposit accounts held by retail customers of the bank, several thousand of which have been opened since 1993. A spokesman for the bank said that in its letter, it has advised holders of these accounts to consult a financial advisor concerning their tax affairs.

The revelation came soon after the Irish Revenue Commission announced that it had netted some 892 million euros in unpaid tax from offshore sources, including bogus non-resident accounts and unpaid DIRT (Deposit Interest Retention Tax) contributions. Commission chairman Frank Daly told the Public Accounts Committee that 111 million euros alone had come from Bank of Ireland trust accounts held in the Channel Islands, and said that it was conceivable that many more millions of unpaid tax will be unearthed in future months.

Back in April of this year, BoI wrote to around 400 customers with accounts at its Jersey branch, warning that the Revenue Commissioners would be looking into their accounts in June to ascertain whether they had evaded Irish taxes. In return for their cooperation with the tax man, the customers were informed that they could reduce penalties payable on those assets from 100% to between 3% and 10% by making a voluntary disclosure.