The Acting Garda Commissioner and the force's principal watchdog have clashed over where the blame lies for the scandal of 1.4 million bogus breath tests.
Josephine Feehily, chairwoman of the Policing Authority, revealed a review is likely to pin fault on implicit performance demands on officers.
But Donall O Cualain, who was installed at the helm of the force after Noirin O'Sullivan's sudden retirement earlier this month, disputed the claim.
Asked if he agreed with Ms Feehily, the Acting Commissioner said: "Based on the evidence I have, at this point in time, no, I do not."
An internal audit laid bare the gross exaggeration of drink and drug-driving checks from 2009 to 2016, with 3,498,400 records on the Garda's Pulse computer system when only 2,040,179 tests were actually carried out.
Ms Feehily is awaiting the outcome of an investigation into the scandal from auditors Crowe Horwath, which will also review the Garda reports.
She said the indications were that it would point to officers facing "implicit demands".
But she warned that it is not expected to unearth a specific order for rank-and-file gardaí to hit bigger targets.
"They are likely to report to us that there was an implicit expectation in relation to breath tests rather than an explicit direction," Ms Feehily told the Oireachtas Justice Committee.
The Policing Authority chief also said that it was difficult to imagine such huge discrepancies in breath test numbers without gardaí of all ranks knowing.
"I think it's difficult to conceive that there wouldn't be knowledge at various levels throughout the organisation," she said.
Ms Feehily gave a damning critique of how she believed Garda management reacted to the startling level of traffic policing at a time of unprecedented cutbacks - supposedly more than 40,000 breathalyser tests every month over seven years.
She said: "I have a sense that it's not an organisation that looks at numbers and says: 'If we're doing that many breath tests and we have this many gardaí and there's only this many people with licences' ... I don't think they think like that."
Ms Feehily urged the Garda Representative Authority (GRA) to come forward with evidence for its claims that rank-and-file officers were acting under duress from superiors when incorrect breath test data was recorded.
The Authority chair added: "I suspect we will be getting indications from Crowe Horwath of a belief throughout the organisation that certain performance was expected but they're unlikely to find, I think, a directive or direction."
Ms Feehily was at the committee after warnings from the Commission on the Future of Policing in Ireland that the appointment of a new Commissioner should be put off.
Commission chief Kathleen O'Toole wrote to Justice Minister Charlie Flanagan this week saying that it would be a serious mistake to recruit a new chief before the reform recommendations are made about a year from now.
She said they will affect the specifications of the job and how the force will be managed.
A standard recruitment process for a new Commissioner should take eight months.
Mr Flanagan said he believed the Government, the Policing Authority and Ms O'Toole's commission would come up with a shorter recruitment timeframe amid concerns an appointment could be two years off.
He added: "I agree the process should not be rushed. It is important we get the right person for the job."
Ms Feehily said questions would have to be asked about how delaying a new appointment would impact policing.
"If I was a candidate, I kind of might want to know what job was going to be laid out before me in the future before deciding whether to apply," the Policing Authority chief said.
"On the other hand ... the idea of a lacuna troubles me."
Among the damaging scandals to have surrounded Ms O'Sullivan's tenure was the revelation of 1.4 million bogus breath tests, the treatment of whistleblowers - in particular Sergeant Maurice McCabe - inaccurate homicide records and irregular financial affairs at the Templemore training college.
The policing reform body, set up under Ms O'Toole - an internationally recognised police chief and former head of the Garda Inspectorate - was charged with advising on radical change in the force amid the welter of controversies.
Ms Feehily praised former commissioner Ms O'Sullivan and said she had a "huge commitment to reform".
She also told the committee: "It is important that I end by underlining that oversight is not an end in itself and it is not a game of 'gotcha'.
"It is about enhancing policing performance with a view to ensuring that communities are safe, that the country is secure and that the Irish people receive the best possible service from the Garda Siochana."