The Revenue Commissioners have vowed to take court action against tens of thousands of people who failed to meet last week's deadline for owning up to having bogus non-resident tax accounts.
Only a relative handful of the 50,000 false account holders are understood to have settled their tax debts in time for the November 15th amnesty.
Final figures on the money handed over will not become clear until next week.
Up to last month only €12.7 million had been received in respect of the tax-dodging accounts, while some estimates of the potential amount due ranged up to €880 million.
The accounts involved were established by people who falsely claimed to be living abroad to avoid paying the Deposit Income Retention Tax on interest, and some date back 15 years.
The November 15th amnesty offered those involved the opportunity to pay in full the interest due without facing extra penalties.
A spokesman for the commissioners said today that they would now go after by recently strengthened tax legislation.
He pledged: "We will now begin using all our new powers to pursue this money."
Those who have not paid up will now, when traced, be subject to all the interest due as well as full penalties.
The spokesman warned: "It is not a question of if they will be caught - but when."
PA