ULSTER Bank has been fined a record €38m for denying thousands of customers tracker rates.
The Central Bank said 5,940 people were denied trackers, while 49 properties had been sold by customers largely due to the overcharging.
Some 29 of these properties were homes.
The regulator said the bank deliberately devised a scheme to avoid giving people good value trackers when they were entitled to them.
It is the largest fine ever imposed by the Central Bank.
It has emerged regulators had to seek to take High Court action to get the bank to provide it with documents related to the scandal.
The bank, which is in the process of closing down in the Republic, admitted to 49 separate regulatory breaches over its treatment of its mortgage customers.
It has now paid out €128m in interest rate rebates, compensation and put the almost 6,000 customers on to low-priced trackers.
The fine would have been €54m but the bank got a 30pc discount for co-operating with the Central Bank.
It appears no individuals will be held responsible for what happened.
In a damning statement outlining the breaches, the Central Bank said Ulster Bank had devised and implemented a deliberate strategy not to provide some customers with their correct tracker mortgage entitlement.
No doubt this was a factor in RBS pulling out of Ireland.