A Bill before the Dáil provides for the appointment of a financial services ombudsman, the Taoiseach said in reply to questions about the AIB overcharging.
Mr Ahern said that in addition to penalty provisions there would be significant extra powers for the Irish Financial Services Regulatory Authority (IFSRA) requiring financial statements from institutions. "There are existing schemes for credit institutions and the insurance industry."
He said the Bill would provide for a single scheme with a more comprehensive remit, and for the first time a statutory framework for this service.
He added that AIB had lodged €25 million with the Central Bank on a good-faith basis at the request of IFSRA.
"We will see where the matter moves from there."
Mr Ahern was replying to Mr Joe Higgins (Socialist Party, Dublin West) who accused the Government of operating "a nauseating double standard by which the economically-powerful may occasionally get mild slaps on the wrist, mainly verbal, but are not really held accountable".
Meanwhile, he added, a young person taking possession of a Garda hat found himself or herself charged with stealing and lodged in jail for many days, with the threat of being kept there longer.
"Is it not the reality that, after seven years of Fianna Fáil and Progressive Democrats' rule, the Ansbacher men and the organisers of the big-bank tax frauds have as much chance of being dragged before a court as the poor stone age men whom the National Roads Authority is now turning up every second week?"
Outlining the background to the case, Mr Ahern said it appeared that AIB noticed the discrepancy two years ago but no action was taken.
"The IFSRA has now launched an investigation into this matter since it is the body there to do so. It has very strong powers, and is actively pursuing the matter with AIB at a senior level. It can impose severe financial penalties."
Mr Higgins said "big bankers and big barristers can rob us with impunity by legal or illegal means, and you and your Government stand over their greed. That is the problem.
"You may wave the odd velvet glove in their direction, but certainly there is no iron fist inside as far as the consequences they have been asked to carry."
