The Revenue Commissioners have collected almost €892 million as a result of investigations into offshore schemes, unpaid DIRT tax and bogus non-resident accounts.
Revenue chairman Mr Frank Daly also told the Dáil Public Accounts Committee that the Off Shore Assets Group of Revenue had recently collected €111 million arising from investigations into offshore accounts and trust arrangements.
"Our initial focus was on the Bank of Ireland trust in Jersey," Mr Daly said.
"At a certain stage when the bank became aware we were interested in it, they wrote to all their customers, advised them that Revenue were on the trail as it were, and reminded them of the standard voluntary disclosure arrangement that are available to anybody who has a tax problem.
"As a consequence of that is that we have had fairly significant disclosure from 254 individuals," he added.
He said it was possible that investigations would eventually result in the collection of more than €1 billion in unpaid taxes.