AIB and its subsidiary EBS have been hit with a record-breaking €96.7m fine by the Central Bank for their role in the tracker mortgage scandal.
Thousands of bank customers were illegally removed from tracker mortgages, which directly follow European Central Bank (ECB) interest rates, and put on variable rates which are more profitable for the bank.
The figure is well in excess of the amount the bank had set aside in preparation for the imposition of penalties.
"The outcomes represent the fourth and fifth tracker mortgage enforcement outcomes, with just one firm-level investigation remaining open in relation to a separate lender", the Central Bank says.
"The fines bring the total sanctions imposed on lenders for tracker mortgage failings to €174m, on top of €737m paid to customers in redress and compensation under the Central Bank-initiated Tracker Mortgage Examination.