The image of National Australia Bank (NAB), the parent company of National Irish Bank (NIB), has been seriously damaged by the revelations that the Irish operation removed money from customers' accounts and the suggestions that it facilitated a tax dodge with an offshore investment scheme, the Australian bank's chief executive, Mr Don Argus, has said.

Speaking on a business programme on Australian television yesterday, Mr Argus followed the initial pattern of NIB's own response to the scandals, blaming the media for exposing what went on.

"We were tried through the television media with a couple of stolen documents out of the National Irish Bank," Mr Argus remarked.

The reference was to the succession of revelations broadcast by RTE News about the bank, backed up by internal letters and documents.

One story centred on NIB's operation of an Isle of Man investment scheme with Clerical Medical International, raising the issue of whether the bank had marketed it as a device allowing customers to hide funds from the eyes of the Revenue Commissioners.

A second story revealed that managers in several branches had ordered staff to deliberately overcharge customers who ran a current account overdraft, believing that the daily calculations of how much interest was really due would prove too complicated for the victims.

"The brand has been severely damaged and we will think very seriously about how we can get some value out of the allegations that have been made against us that have proven not to be correct," Mr Argus told Business Sunday on Australia's Channel Nine.

After the CMI revelations, NIB accused RTE of making "sweeping allegations" against the bank on the basis of "selective information".

"The bank has been pilloried and harassed by RTE on an almost daily basis, and its bona fides questioned," NIB had said in a statement. But after details were made public about how account holders were overcharged, the bank wrote all of its customers, saying that it was treating the allegations with "the utmost seriousness".

There are now several investigations into the bank's operations, including probes by the Revenue Commissioners, the Central Bank, the two authorised officers appointed by the High Court at the request of the Government, and the bank itself.

The authorised officers, Mr Tom Grace and Mr Justice John Blayney, are due to produce an interim report by June 22nd.

Yesterday Mr Argus said NAB, Australia's most profitable bank, had responded to requests from the Irish Central Bank but had yet to receive a reply.

"I can assure you there is no systemic problem in the way the bank was run."

Last week, NAB posted a 15.9 per cent drop in interim profits to March of Aus$958 million (£428 million), but said it was optimistic about the full year. The bank said its European operations continued to perform strongly.

In Dublin, a spokesman for NIB would not comment on Mr Argus' remarks.