The South East region had the highest number of discrepancies in recorded breath tests, according to figures published today.
The Garda Commissioner Noirin O'Sullivan and the Government have been under mounting pressure in recent days after it was revealed that almost a million extra breath tests were recorded.
According to the figures released by the Gardai, 332,463 breath tests were recorded on the Garda PULSE system in the South East region between November 2011 and October 2016. However, only 127,291 breath tests were recorded by the actual breath test devices in the South East during the same period. That's a percentage difference of +153%.
It's still unclear what caused the errors.
The review of roadside breath tests for five years to 2016 found the Medical Bureau of Road Safety recorded 1,058,157 tests had been carried out but the Garda recorded 1,995,369.
In an earlier statement, the Policing watchdog said: "The Authority is alarmed at the scale of the discrepancies disclosed between actual alcohol tests administered and the numbers recorded by gardaí.
"This is not just an academic statistical matter, it is an ethical one. It raises serious questions of integrity for the Garda Siochana organisation and combined with previous issues regarding inflated activity levels, erodes confidence in the credibility of Garda data generally.
"It again raises concerns about management and supervision... In the view of the Authority, the scale of the discrepancy is further evidence of deep cultural problems within the Garda service - a culture in which such behaviour was possible."
The Policing Authority said the Garda had admitted that there are possible wrongful prosecutions and convictions.
Some 830,000 cases have been reviewed by the force and people affected are being contacted but the watchdog said there are potentially thousands of people caught up in the errors.