The Public Accounts Committee has been told it does not have the legal right to investigate allegations of tax evasion contained in a dossier the committee received last week.
The PAC has referred the dossier to Gardai, according to Labour TD Joe Costello. The PAC has also written to Minister Richard Bruton to request he send the dossier to the Revenue Commissioners.
The committee has been meeting behind closed doors to take legal advice on the dossier.
TDs have been told that the documents they received are not protected by whistleblower laws - and that they cannot interview the whistleblower himself.
It is understood that the Dáil would need to pass a formal resolution in order to give the PAC the power to investigate.
In the meantime, TDs have asked the public spending watchdog to update them on the collection of taxes due from the holders of accounts at Ansbacher bank.
Earlier today Mary-Lou McDonald TD told the Dáil that “household names” from the now defunct Progressive Democrats and Fianna Fáil are among those named in the dossier.