Financial watchdog IFSRA has found that some AIB staff and management were aware that the bank was overcharging thousands of foreign exchange customers.
AIB has said it accepts today's report.
IFSRA said there were at least seven opportunities for staff and management to inform the relevant regulators between 1998 and 2004. 'This was not done,' the report said.
IFSRA Chief Executive Liam O'Reilly described the failures uncovered by the investigation as 'completely unacceptable', adding that such practices would not be tolerated.
However, he said it was not possible for the watchdog to impose any sanctions, though new legislation would allow this to happen in any future cases.
The report did not name the senior bank officials who may face disciplinary action over the handling of the affair, because due process within AIB is still underway.
However, it has ordered AIB to apply disciplinary sanctions against individuals found responsible.
It has also called for a full review of AIB's pricing policy and a centralised register of all charges levied on products.
Overcharging totals €34.2m
The report found that the total amount of overcharging by AIB, including interest, came to €34.2m.
€25.6m of this related to the foreign exchange issue, and half of this has been repaid.
The bank confirmed to RTÉ News earlier this year that it had been overcharging thousands of its foreign exchange customers and that the practice had been going on for years.
In conjunction with IFSRA, it agreed to set up an independent inquiry into the affair and also agreed to pay back its customers.
AIB accepts report
Speaking on RTÉ's News At One programme, AIB Chief Executive Michael Buckley said the bank accepted the report and would not make any excuses for its failures.
He declined to say how far up the bank's chain of command knowledge of the overcharging had gone, but confirmed that he had not known of it.
This afternoon, the Minister for Finance, Brian Cowen, welcomed the publication of the IFSRA report. He said it would be taken into account in the development of future financial services legislation.
Labour's Finance Spokesperson Joan Burton expressed disappointment at the contents of report. She criticised the document for failing to identify the AIB management responsible.
The Green Party's Finance Spokesperson Dan Boyle said the individuals responsible must be identified.
You can download the report in pdf format from the Irish Financial Services Regulatory Authority's website
