The Revenue Commissioners are launching a formal investigation into the Offshore Investment Trust of Bank of Ireland customers.

Other banks are to be targeted too.

The Revenue is to petition the High Court for an order requiring full disclosure from Bank of Ireland of the names and details of all offshore trust investments involving their customers.

Bank of Ireland says it will be legally obliged to comply.

The bank has written to customers who will be affected, advising them of the benefits of a full voluntary disclosure of any tax liabilities that may be due on foot of their Investment Trusts.

RTÉ understands that this is just the first in a series of similar investigations that the Revenue Commissioners will be embarking on and that the offshore trusts activities of Irish residents through other banks will be similarly targeted in the months ahead.

In another development, the Revenue Commissioners have disclosed that they collected another €40m from the holders of bogus non-resident bank accounts who made tax settlements in response to the latest batch of Revenue letters demanding settlement last month.

This brings the total amount collected from the holders of bogus non-resident accounts to €160m and the total collected on foot of the DIRT tax inquiry to €600m.