The report into whether there was an attempted cover-up at AIB on overcharging is not now expected until the end of the year

The report had been expect this month, or next month at the latest.

A team of investigators from Deloitte, who have been looking into the issue of how the overcharging at AIB came about and how it was not noticed over an eight-year period, completed their work last week.

The results of their inquiries, which were overseen by a former comptroller and auditor general, Mr Lauri McDonnell, will now feed into the ongoing inquiry being conducted by the Irish Financial Services Regulatory Authority (IFSRA).

"We are going to spend some time examining the Deloitte findings. We hope to have the final report by the end of this year," a spokesman for the authority said yesterday.

He refused to say if legal difficulties over naming anyone found responsible for any failings discovered were holding up the report.

The authority is training staff in the procedures that must be implemented to protect people's constitutional rights when they are the subject of inquiries that could result in negative findings.

An interim report published by IFSRA in July found that AIB had overcharged customers in the period from September 1995 to April 2004.

A total of €34.2 million is being returned.

The report also found the bank had failed to notify the regulator as required.

It was said in July that a second report would be published in the autumn, possibly in September. The report was to deal with such key issues as: whether someone had consciously set out to overcharge AIB customers; whether anyone had noticed the overcharging; and whether anyone had sought to cover up the issue.

In July the chief executive of IFSRA, Mr Liam O'Reilly, said it "wouldn't be having an investigation if we didn't have grounds for believing there was some sort of cover up".

AIB chairman Mr Dermot Gleeson SC said, given that the bank had for eight years charged customers higher fees than it had notified to the regulator, "you'd have to ask questions".

An investigation is also being conducted by IFSRA into the use of offshore accounts by AIB executives, certain dealings in shares using AIB Investment Managers, and associated Revenue issues. The issues are entirely unrelated to the overcharging controversy and arise from events in the late 1980s and early 1990s.

In July Mr O'Reilly said these issues might be dealt with in a separate report or in the same report as the one dealing with the overcharging issue, depending on whether they were completed at around the same time.

Yesterday a spokesman for IFSRA said it had still not been decided whether two separate reports would be published, or whether all the issues at AIB would be dealt with in a composite report.