Update 6pm: The acting Garda Commissioner has accepted that public confidence in the force has been damaged.
In a statement this evening, Dónall Ó Cualáin said they're determined to ensure that these failings cannot happen again.
"An Garda Síochána takes the findings of the Crowe Horwath report on behalf of the Policing Authority into issues relating to the FCPN system and recording of breath-tests very seriously.
"Just as Assistant Commissioner O’Sullivan’s report into these matters did, the Crowe Horwath report has also found unacceptable failures in our systems, processes, internal oversight, supervision, governance, management and culture. These were collective failures and we must now all work together from top down to bottom up to resolve them.
"An Garda Síochána accepts the damage this has done to public confidence. We fully recognise the importance of public support and confidence in the delivery of an effective police service. It has always been the cornerstone of An Garda Síochána and vital to the delivery of a police service that protects and supports communities.
"That is why we are absolutely determined to ensure that such failings cannot happen again. Our strong focus now is on changing our systems, practices, behaviours and culture. This process has already started and will continue at pace until all matters are resolved. "
Earlier: True scale of breath test scandal may never be known, police watchdog warns
It is likely the true scale of gardaí recording bogus breath tests will never be known, the force's top oversight body has warned.
The Policing Authority said the latest review of the scandal estimates that there were another 404,700 false records on top of the near 1.5 million already identified.
The watchdog launched an excoriating assessment of the culture and standards across the force and singled out the top brass in the force as responsible.
And in one of its most damning findings it warned that officers should not need training to be honest.
"The fact that the behaviours outlined ... were endemic and seemingly went unnoticed and unchecked over nearly a decade is a serious management and governance failure for which top Garda management are responsible," the watchdog said.
Garda chiefs have been asked to launch further investigations into 2,134 drink and drug-driving checkpoints and associated data which contributed to the massive over-exaggeration of breath tests statistics from 2009 to 2016.
Chairman of the Policing Authority Josephine Feehily, said the issue for the watchdog was also about integrity and culture.
She said: "Unfortunately, the Authority cannot offer an assurance to the community that these problems could not recur, although we hope that they won't."
Ms Feehily said inadequate supervision and poor performance management is at the heart of the controversy.
But she added: "These cannot be explained away simply by issues relating to lack of training and resources."
The report warned that the entire affair raises questions about the way gardaí go about their daily work.
The Policing Authority raised concerns that the Garda has yet to grasped the importance of the issues which were identified as far back as 2015.
It said Garda management looks at the issues as being primarily administrative and technical. It also warned that the excuses of poor training and complex legislation did not lead to figures being underestimated.
"The Commissioner needs to now visibly lead on providing a permanent solution to the issues of culture, supervision and performance management outlined in this report and indeed which also pervade many external reports relating to the Garda Siochana over the past 20 years," it said.
The Policing Authority said there was a culture in the force that displayed a casual approach to data and a lack of appreciation of its value. It said that enabled unethical behaviour by gardaí.
"Nothing has displaced the truism that no training is required for behaving honestly and ethically," the authority said.
The Authority raised concerns about why no-one questioned the performance of gardaí policing the roads at a time when budgets were being cut.
"It is unlikely that the illogical nature of this went unnoticed and yet it appears it was not raised - nobody spoke up.
"If it did go unnoticed, it raises further questions with regard to management capacity to understand and know what is going on in their organisation," it said.
The report for the Authority by consultants Crowe Horwath found some senior Garda management did not know what was in their policing plans and there was a lack of proper supervision probing from sergeant level up to commissioner.
It said it painted a disturbing picture that gardaí have significant problems with supervision and that there was a confidence that they would not be held to account.
And the Authority dismissed the Garda's argument that the number of sergeants was slashed in the recession, adding that the ratio of gardaí to sergeant remained relatively stable.
It also found many divisional officers failed to respond to the Commissioner adequately or at all when asked to make sure checkpoints were being properly run.
The Garda's internal review, which identified the 1.5 million bogus tests, also came in for criticism for failing to analyse management inadequacies.
The Authority said Garda management do not fully appreciate the impact the scandal has had on public confidence not just for roads policing but how the entire force is managed and governed.
It said: "It is a source of concern that there appears to have been no appreciation of the importance of knowing the accurate percentage that failed tests represented of the total number tested.
"Nor did there appear to be any understanding of the importance of that information in the shaping of public policy in an area of behaviour that causes so many deaths and injuries on the roads every year and blights the lives of families the length and breadth of the country."
The Authority said it was troubling that IT and technical fixes do not give the necessary assurance that the issuing of fines, penalty points and summonses or reporting drink and drug driving checkpoints cannot be abused in the future.
Fianna Fail justice spokesman Jim O'Callaghan called for beefed-up oversight powers for the Policing Authority with the bogus breath test scandal worse than previously thought.
"Unfortunately, the poor performance of senior management in An Garda Siochana remains at the fore of these repeated controversies," he said.