AIB and the Irish Financial Services Regulatory Authority (IFSRA) have received almost 2,500 phone calls from customers who believe the bank may owe them money as a result of its €25 million foreign exchange charge blunder.
As soon as news broke of the latest scandal to hit the State's biggest bank last week, both IFSRA and AIB itself set up helplines to aid customers who believed they could have been overcharged.
Following both lines' first week of operation yesterday, it emerged that the two organisations received a total of 2,450 calls. AIB said that it received 1,900 phone calls from customers, while IFSRA revealed that 550 people had contacted its helpline.
The bank and the regulator said it was likely that some callers had contacted both, but neither could say what the exact level of duplication was. IFSRA is also referring calls to AIB, where it believes this is appropriate.
AIB admitted last week that between 1994 and last month, it charged a fee of 1 per cent on non-cash foreign exchange transactions of over €635 (£500), despite the fact that it had regulatory approval for a charge of just 0.5 per cent.
It also emerged yesterday that the bank failed to tell the State's consumer watchdog in 1998 that it had been overcharging customers, despite the fact that the regulator specifically asked if it was applying the correct fees to all transactions.
Former government spending watchdog Mr Laurie McDonnell is to lead AIB's internal investigation into the affair. He will begin work immediately and is due to finish in mid-June. The bank could not say last night if it would publish his report, as both IFSRA and Mr McDonnell himself will have a role in deciding this.
Mr McDonnell served as Comptroller and Auditor General (C&AG) between 1981 and 1994, when he retired. The C&AG is a constitutional office that audits and monitors State spending to ensure that the taxpayer gets value for money.
Mr McDonnell was born in Co Tipperary in 1932 and was named after Cardinal Laurie, who was Papal Legate to the Eucharistic Council of that year. Before his appointment to the C&AG's office in 1981, he served as assistant to his predecessor.
He created a political controversy in the early 1990s when he highlighted the potential for abuse in the distribution of National Lottery funds.