A Garda internal audit report has raised concern over the force's management of a multi-million euro IT contract with the consultancy firm Accenture.
In the report, the Garda Internal Audit Section (GIAS) also said that "no assurance" can be given that procurement rules were being properly followed on major IT contracts.
The report found that elements of an IT contract with the consulting firm Accenture were "not best practice".
Accenture was paid €26.5 million alone in 2016, for work done across various projects, the report reveals.
In particular, GIAS said there was a lack of a paper trail over a key financial agreement between gardaí and the firm, according to the report; a copy of which has been obtained by RTÉ's This Week programme.
The internal audit was finalised and signed-off by the head of Garda audit servces Niall Kelly last August.
The auditors examined how contracts were managed by An Garda Síochána and the report makes no criticism of Accenture of the service they provide to An Garda Síochána.
GIAS auditors found there was "no documentary evidence" to show how the force ended up agreeing to revised rates of pay for different grades of skilled Accenture personnel, when updating the terms of their original 2009 contract in 2016.
When the audit team asked Garda management how the new rates of pay with Accenture were decided upon, they were told the new rates had been "verbally agreed" between a senior manager in the force and Accenture, with no paper trail on the force's side.
"Best practice would have ensured documented records of these discussions and agreements" the report concluded.
The report also found that "a much weaker system of accountability" was applied to how contractors working for Accenture were required to record the hours that they had worked, compared to other private sector contractors.
It found that, unlike other firms hired by gardaí, some contractors engaged through Accenture did not electronically record the hours they worked on behalf of the force.
GIAS noted that the requirement on private contractors to record the hours they had worked on IT services, applied to all "with the exception of those engaged by Accenture".
Auditors said they were satisfied, "with the exception of Accenture," that controls over payments made to private IT contractors were effective.
GIAS concluded that they could provide only "limited assurance that adequate controls exist in the management of resources in relation to the largest contractor", which was Accenture.
On the issue of procurement concerns, the report found that several major contracts had not been re-tendered, despite the original terms of the contracts having passed.
This applied to the contract with Accenture, which was agreed for five years in 2009 but had been since extended without going back to full tender.
It highlighted a number of other contractors whose services had also not been re-tendered for competitive bids in several years.
GIAS said that these practices posed a "high risk" to the proper operation of the ICT division in An Garda Síochána and it was on this basis they could provide "no assurance" that proper procurement rules were being followed by the force's IT section.
In their written response which was included within the audit report, senior management in the Garda ICT division "expressed concern" about the adequacy of resources "in terms of both capacity and capability for the appropriate implementation of controls over management of projects".
Garda ICT management also said that it was their intention to re-tender contracts, where deemed necessary, using the office of government procurement, who they said had been developing a special framework for the type of service provided by these contractors.
RTÉ asked the Garda press office a series of questions during last week about whether any of these contracts had since been re-tendered, the circumstances in which revised fees had been verbally agreed and what if any examination would be carried out into this practice.
However the press office said it was unable to respond before this weekend but would endeavour to do so in due course.
RTÉ also sought information from the Department of Justice and Department of Public Expenditure and Reform about whether either of them had sanctioned the extension of contracts whose original duration had lapsed.
Both Departments said the question was not for them to answer and should be directed to the other department, and to An Garda Síochana.
Vice chairman of the Dáil's Public Accounts Committee Alan Kelly said the revelations in the report were "very disturbing" and raised questions about how these procurement practices and contract management issues had been allowed to occur.
He said the PAC would "most definitely" be examining this report and the issues raised by the internal auditors.
Responding to the details of the report, Independents4Change TD Catherine Connolly also said the issue needed to come back before the Public Accounts Committee "as a matter of urgency".
"It occurs to me this is a common theme through every single public body which comes before us; non-compliance with procurement rules, although the value of the non-compliance is at a level here we haven't seen before," she said.
"So this is a very serious matter, that has to come back before us".