The Revenue Commissioners received more than 2,300 disclosures of overseas income ahead of a deadline for declarations this month, according to the Minister of Finance.
In response to a Dáil question from Fianna Fáil's Michael McGrath, Michael Noonan said that the disclosures had a value of more than €70m.
Mr Noonan also said that some disclosures are still being processed, which means the final number could be even higher.
People who made a voluntary disclosure of overseas income to Revenue by May 4 faced a discounted penalty of 10%, while they also escaped the risk of prosecution.
However those who did not make a disclosure in time could now be hit with higher penalties and having their name listed in the Tax Defaulters' List. They could also face potential prosecution.
Michael McGrath said the number and value of voluntary disclosures made to the Revenue is very significant and is a stark reminder of the level of non-compliance related to offshore assets.
"The Revenue need to use their full statutory powers on those who have not taken the opportunity to avail of the more lenient treatment by making a voluntary disclosure before the deadline," he added.