Profound disagreement between senior gardaí over reforming the policing college at Templemore has undermined the ability to resolve problems, a watchdog report said.
The force is split between reformers and those for whom protection of reputation is paramount, the Public Accounts Committee (PAC) said.
TDs criticised a culture of withholding information and keeping issues internal. They said the aim was to avoid external scrutiny of very significant financial issues at Templemore.
Garda Commissioner Noirin O'Sullivan also came under fire after disclosing that informing relevant authorities was delayed in 2015 and 2016 pending the gathering of information.
The committee report added: "It is the view of the committee that what is apparent is a profound professional disagreement among senior management about how to address the very significant financial issues in the Garda College."
A damning internal audit of the financial and accounting practices in Templemore by the head of the Garda's internal audit unit and a civilian official in the force, uncovered dozens of bank accounts, a €5 million surplus and investment policies related to the college.
The Public Accounts Committee also examined issues raised over the leasing out of land and some of the money being spent on entertaining and retirement gifts.
There is also a transfer of €100,000 to the Garda Boat Club.
Despite this, information was not shared by gardaí.
The committee said transferring large amounts of money from a bar account to the Garda College restaurant account was irregular and unacceptable.
It questioned the appropriateness of the Garda College Bar and Restaurant holding credit union accounts.
And it said an independent investigator was only granted access to credit union accounts earlier this month.
The committee said high-level disagreement within the force over what to do about Templemore finances appeared to be between those who wished to preserve the status quo and for whom protection of reputation, including that of the Garda and the College, was the principal concern, and those who wished to implement what they considered to be the necessary reforms even if this involved reputational risk.
"It is the view of the committee that the level of disagreement is such that it will undermine the ability of senior management to fully resolve issues and complete the implementation programme unless resolved by An Garda Siochána."
Management was given several opportunities over the past decade to address the problems but failed to do so, the review revealed.
Commissioner O'Sullivan said the senior management team was new and that, in her opinion, tensions were inevitable during large organisational change.
Members were "disturbed" by the apparent practice within senior Garda management of not sharing pertinent information with its own internal audit section, auditors or the Justice Department.
"The committee considers this a failure of corporate governance."
Members said it was unacceptable for the Commissioner to delay informing the relevant authorities.
The Garda Audit Committee was not informed for two months after the Commissioner was made aware of the issues, despite there being a meeting of the Audit Committee in July 2015.
The auditor general was not informed until 10 months after the Commissioner became aware.
