An investigation found some gardaí were exaggerating figures by 300%
There are fresh calls for the Garda Commissioner Noirin O'Sullivan to step down after the latest news about fake garda breath tests.
The Government has, however, expressed confidence in Commissioner O'Sullivan.
It comes after a report found that the recording of almost 1.5 million fake tests has undermined confidence in the organisation.
An investigation has discovered an extra 500,000 false tests, and found some gardaí were exaggerating figures by 300%.
A separate report has examined cases where around 14,700 people were issued a court summons instead of a fixed charge penalty.
It found that the current penalty system "is not working as efficiently and effectively as it should".
Both reports have been published on the Garda website this afternoon.
Responding to the reports, Commissioner O'Sullivan observed: "Assistant Commissioner [Michael] O’Sullivan’s reports identify failures in our systems, processes, oversight, supervision and management. These failures are completely unacceptable and all of us in An Garda Síochána must now take responsibility for ensuring this cannot happen again.
"I agree with Assistant Commissioner O’Sullivan when he writes that these failures, particularly in relation to breath tests, reflect poorly on the professionalism of the organisation and are damaging to public confidence. It is vital that An Garda Síochána continues to have the public’s confidence and support in order to carry out our work," she added.
The Government has again backed the Commissioner, despite fresh opposition calls for her to resign.
Speaking to 3News, Taoiseach Leo Varadkar said: “The government has confidence in the Garda Commissioner - I've said that before and that is the position of the government. It remains the case [despite today's revelations].
"Bear in mind the problems and the unacceptable practices that arose when it came to falsifying breath-tests began before the current Garda Commissioner became Commissioner."
The Justice Minister Charlie Flanagan briefed the Cabinet on the reports earlier today.
In a statement this afternoon, Minister Flanagan said he was "greatly disturbed" by some of the findings.
He explained: “The reports identify serious and concerning problems in the operation of both the Mandatory Alcohol Testing checkpoint system and the Fixed Charge Processing System.
“I am greatly disturbed by findings that indicate that between 3% and 9% of the PULSE records relating to MAT/MIT checkpoints are estimated to have inflated breath tests. I note that any potential such cases identified in this report have been referred to the relevant Regional offices for further investigation and sanction where appropriate."
He added that the force has put a "range of measures in place" to address the issues highlighted, and said he will take "all appropriate action" when he receives a report on the issues from the Policing Authority.
Tánaiste Frances Fitzgerald, who was justice minister when the false figures were first discovered, also said it is deeply disturbing.
"The information that came out last year about the breath tests and the other issue clearly was unacceptable.
"I understand we now have the reports - Minister Flanagan has them - I haven't seen them yet so I'll wait until Cabinet to hear what is actually in those reports.
"But of course the suggestion that you make up an additional 500,000 would be deeply disturbing".
Sinn Féin justice spokesperson Donnchadh Ó Laoghaire says Cabinet needs to examine the future of the commissioner.
"It raises serious questions, yet again, about the culture within the senior levels of An Garda Síochána - there seems to be a culture of impunity.
"Nobody has been held accountable for this, that's simply not acceptable.
"I think it raises, again, further questions about Garda Commissioner Noirin O'Sullivan - who I would reiterate needs to go".
Reporting by Sean Defoe, Jack Quann and Stephen McNeice