The directors of financial institutions had an "overly relaxed attitude" towards discharging their duties in respect of DIRT tax, the report says.
It says that considering the "eminence" of many directors, it is surprising they did not bring a "greater weight to bear" when it came to ethical standards.
The report also criticises industry bodies who "exercised no role in developing a code of practice that would have addressed ethics in banking". It points out that banks regard corporate governance and ethics as "being outside the remit of industry-representative organisations."
In light of the events disclosed, the committee finds it surprising that board members of banks and building societies "have not recognised the need for an effective industry-wide forum to set and enforce standards".
It adds that "the deliberate exclusion of industry representative bodies from any role in regulation of banking has negative repercussions for industry standards".
In terms of auditors of banks, it states that "a number of serious defects and weaknesses in relation to the statutory external audit function" exist. These "contributed to the continuance of the bogus non-resident problem and these require to be addressed urgently".
The report reflects that directors of banks "may not place a significant value on the external audit process" and this is reflected in the relatively low level of audit fees in comparison with taxation advice or consulting assignments.
"In such a situation, there is a risk that fees are not set at a level appropriate to maintaining the confidence required to support limited liability, incorporation and the reliability of financial statements," it states.
"In short, the shareholder can be the loser in a situation where audit fees are solely at the discretion of the directors," it adds.
External auditors were criticised for "the small level of sampling and fieldwork undertaken".
The report focuses on the role of the main industry body, the Irish Bankers Federation (IBF). It describes this as "principally a loose discussion forum and a lobby group directed at influencing public policy", but with no "effective role in setting standards or ethics".
The report includes an exchange between the chairman of the committee, Mr Jim Mitchell, in which he asked Mr Kevin Kelly of the IBF if there were any ethical standards in the organisation. "No. It's a loose association in a way," replied Mr Kelly.