Bank of Ireland's senior executives tried to set an ethical tone on DIRT, but there were serious breaches of this over a number of years in many branches, the Public Accounts Committee (PAC) has said.
In its report, the committee said the State's second largest bank failed to draw the conclusions it should have about customer tax evasion from its own audits.
A spokesman for Bank of Ireland said last night the company had acknowledged during the hearings that it had a problem with DIRT liability and was chastened by the report. But he said the bank was grateful the report had concluded that, in relative terms, Bank of Ireland had behaved well.
The bank estimates that its liabilities to the Revenue Commissioners will probably total £1 million. The PAC found that "the most senior executives in the Bank of Ireland did seek to set an ethical tone for the bank, and unsuccessfully sought Revenue assistance in promoting an industry-wide code of practice".
"Notwithstanding the Bank of Ireland's formal commitment to compliance, there were serious breaches throughout the branch network over a number of years," the committee said.
The PAC is also critical of how the Investment Bank of Ireland (IBI) subsidiary strived to minimise the tax liabilities of customers.
"The competitive imperative gained supremacy over the compliance ethos and the bank ought to have sought guidance from the Revenue in this case and failed to do so," the report concludes.
The Bank of Ireland spokesman said there was nothing wrong with the company trying to help customers avoid paying tax, adding that the specific issue at IBI may not have been adequately explained at the hearings.
"We did have extensive documentation problems - we don't have any, nobody else has any - and in the end of the day there is no excuse for it," he added.