Detailed information regarding claims of inappropriate accounting at AIB Capital Markets in 2007 and in early 2008 has emerged.

The Sunday Tribune has been shown information that suggests a series of account reconciliations were handled in questionable ways at the bank's major division over many months.

According to AIB sources, over-payments by clients of the bank in some instances were used to mask errors and interest charges in other accounts. AIB used customer names, including that of Moody which is understood to refer to Moody the US bank, in these practices. The bank's clients were unaware of the practices.

Other accounts of big international banking clients were used in the same manner, according to information seen by this newspaper.

Sources suggest that the inappropriate reconciliations amounted to tens of thousands of pounds sterling.

"Accounting entries were amended to represent authentic account entries," said one AIB source. The Sunday Tribune understands that the inappropriate accounting did not involve fraudulent behaviour in any way. Questions involving reconciliations at AIB Capital Markets were first raised at an employment appeals tribunal hearing in April by a former AIB Capital Markets employee, Brian Purcell, who is fighting his dismissal by the bank.

The hearing heard that Purcell, after using the bank's internal Speak Up policy to report suspected accounting abuses at its Capital Markets Division, was subsequently dismissed. Counsel for AIB told the hearing his dismissal was "fair" and only followed several inquiries and internal appeals after Purcell admitted to accessing his colleagues' banking details.

In questions put to AIB, the Sunday Tribune asked whether the bank had informed the Financial Regulator about any of these matters in 2007 or 2008 and whether the bank had launched an internal audit or internal inquiry at its Capital Markets division and whether any staff had been disciplined.

In a statement, AIB said that the allegations about inappropriate accounting were made by a former member of AIB staff following his dismissal from the bank. "All have been fully investigated and found to be without foundation," an official said.