The industry-wide probe concerns customers who should have been given the option of a cheaper "tracker" mortgage that follows the low European Central Bank rate or kept on a better rate. The total number also includes 7,100 cases remedied following a prior investigation.

The Central Bank said 459 million euros had been paid in redress by the end of March, an increase of 162 million euros since the end of last year, including 11 customers who received in excess of 500,000 euros each due to loss of ownership.

All but 12 percent of customers impacted to date have received redress and compensation offers, with the remainder expected to receive theirs by end-June.

Some further increase in the total number of impacted customers is also expected before the examination is concluded, the central bank added.

"We recognise the devastating effects that lenders' failures have had on people. We're using our powers to force the banks into remedying the scandal they caused," Irish Central Bank Director General of Financial Conduct Derville Rowland said in a statement.

(Reporting by Padraic Halpin; Editing by Catherine Evans)