AIB chairman Mr Dermot Gleeson SC and AIB chief executive Mr Michael Buckley will face questions today from an Oireachtas committee about the culture in the bank.
AIB has promised to repay some €34.2 million to customers who were charged more than the advertised rate for foreign exchange and other services.
The bank refused to meet the committee last May because the initial investigation into the overcharging was still under way.
Mr Gleeson pointed out in a letter to the chairman of the Joint Committee on Finance and the Public Service, Mr Sean Fleming TD, which was circulated yesterday to committee members, that the investigation was incomplete and the "final conclusions" were not yet drawn.
He said: "Because of roles that the chief executive and I, as chairman, have in appeal phases of certain internal disciplinary processes in AIB, we have not had access to the second Deloitte report insofar as it refers to the roles that individuals may have had in the notification failures in relation to foreign exchange charges.
"The board of AIB set up a special committee to determine our response to the inquiry and the committee's remit includes the consideration of any appropriate disciplinary proceedings.
"The [Oireachtas] committee will appreciate that legal constraints arising from obligations of fairness will oblige us to refrain from discussing these disciplinary matters."
Mr Fleming said he had "no problem" with Mr Gleeson's letter but was interested in the general area of discipline within the bank. "In terms of the general culture in the Irish operation, it appears that no heads have ever rolled," he said.
Fine Gael deputy leader and finance spokesman Richard Bruton said he would be raising several issues at today's meeting. These include accusations that AIB and other banks are making "super-profits" from customers through investment deal allocation and the creation of offshore companies.