Reaction:The findings of the High Court inspectors' report are "deeply disturbing", the Tánaiste, Ms Harney, has said.
The damning 400-page report highlights breaches of company, insurance and tax law in the 1990s.
"It is simply unacceptable that one of the countries leading financial institutions should breach that trust and behave in this manner," Ms Harney said.
The Tánaiste, Ms Mary Harney
"What went on in NIB was not some minor oversight. What I find most shocking is the culture which prevailed at the highest level in the organisation which allowed and even encouraged wrongdoing.
"Too many people, and indeed the bank itself, saw themselves as above the law and felt that they could simply get away with this," she said.
The Tánaiste said it was up to the Director of Public Prosecutions and the courts to decide on punishment for those involved.
"I will leave the issue of sanctions to those whose job it is to consider such matters," she added.
The Irish Financial Services Regulatory Authority (IFSRA) warned it would take any action deemed necessary following the outcome of the report. "The type of activity described in the High Court inspectors' report is utterly unacceptable," chief executive Mr Liam O'Reilly said.
"As a regulator with a strong consumer mandate, we are absolutely determined to ensure that there is no place for this type of activity in the financial services industry of today."
Fine Gael's finance spokesman, Mr Richard Bruton, said the report "lays bare the disgraceful manner in which an Irish banking institution could systematically and remorselessly rip-off its customers and the taxpayer".
He said IFSRA "must make full use of the powers it has been granted and proactively pursue a compliance agenda within the Irish banking sector."
"That means that a different and higher standard of work practice must apply in the future.
"In addition, I question the Minister's decision to cap penalties that IFSRA can impose at €5 million. This is in sharp contrast with breaches of Competition Law, where under the influence of tougher international regimes our penalties can rise to 10 per cent of turnover."
Labour Party leader Mr Pat Rabbitte said the report painted a "truly shocking picture of systematic dishonesty, tax evasion and theft.
"Not only was the bank stealing from its own customers by raiding their accounts through the improper application of fees and interest charges, but it was also robbing the taxpayer by the widespread use of bogus offshore accounts," he said.
Mr Rabbitte said recent events "in regard to other financial institutions show that there is long way to go before the public can again have full confidence in the financial institutions.
"The report also shows that Minister for Finance, Charlie McCreevy, who had such a dismissive attitude to the original story broken by RTÉ was either asleep at the wheel or simply did not wish to delve too deeply into this area for fear of what he would find."
The Green Party chairman, Mr John Gormley, said a commission on banking must be established "as the Central Bank, the responsible supervisory authority at the time, clearly failed to protect customers' interests".
Mr Larry Broderick, general secretary of the Irish Bank Officials' Association, said the inspectors' report highlighted the most deplorable activities in the country's banking system.
He called the report "a damning indictment of totally unacceptable and unethical practices that occurred in National Irish Bank.
"Those responsible should be held to full account for their actions and it is important that current employees are not scapegoated for the sins of the past," he added.
Current NIB chief executive Mr Don Price said the bank had been working for more than six years to deal with the issues in the report, co-operate with the investigation, develop reimbursement schemes and implement a wide-ranging compliance programme.
"The events under investigation go back a long time. We have literally rebuilt National Irish Bank from the ground up. It is now a very different organisation," he said.
"While co-operating and working with the investigation, we also instigated a comprehensive change programme and introduced new systems and controls, transforming how we operate as a business."
