Former AIB group internal auditor Mr Tony Spollen has said that he is refusing to discuss details of his work within the bank with anyone, including the authorities investigating the extent of bogus non-resident accounts.

Mr Spollen would only say yesterday that he had "made it clear to any authority that has approached me that I will not talk about AIB or for AIB". He insisted that "his absolute and total loyalty is to AIB".

He was financial controller at the group for 17 years before he became group internal auditor, a post he held for five years until 1991.

Sources said that the investigation branch of the Revenue Commissioners approached Mr Spollen some weeks ago seeking his cooperation in the examination of the AIB bogus non-resident accounts. It is understood that the investigators were told that Mr Spollen could not become involved in their investigation, but that he was prepared to attend a meeting between AIB and the Revenue Commissioners if requested by AIB to do so.

Sources close to Mr Spollen said yesterday that he has been very "upset and hurt" by the publication of internal letters sent by him as group auditor to the audit committee and any suggestion that he could have been involved in leaking the documents concerned. They said Mr Spollen's job as internal auditor at AIB involved monitoring the operations and reporting internally to the group chief executive and the group audit committee. They insisted that he was never in "a whistle blowing role" as far as any external authorities were concerned. Any letters he signed were directed internally and followed his direct reporting lines, they said. In these letters Mr Spollen dealt with the existence of the bogus non-resident accounts in bank branches which were set up to evade deposit interest retention tax (DIRT), alleged management inaction on these accounts and the extent of the tax owed by the bank on these accounts. Last week Magill magazine published a letter dated April 5th 1991 from Mr Spollen as group internal auditor to the group audit committee. The letter stated: "The Group Taxation Department has informed me that an Amnesty cannot be given without legislation going before the Dail: the group therefore has a contingent liability of c.£100 million in respect of DIRT."

Following his letter a top level committee of AIB directors was set up to examine the issues raised. The committee established by then chairman Mr Peter Sutherland rejected Mr Spollen's assertion that management had mishandled the treatment of non-resident accounts.

It is not clear how the committee judged the internal auditors assessment of the alleged tax liability. Mr Spollen resigned from AIB soon afterwards.