Dozens of people accused of drunk driving will breathe a sigh of relief after a technical flaw caused hundreds of breath testing devices to be pulled from police service.
Four hundred of the Drager 7510 models were introduced in July, mostly in rural areas, police said.
The recall meant about 80 evidential readings were affected, police said, and tickets or prosecutions incorrectly made would be withdrawn.
The hand-held screening devices would now be sent for further testing, police said this afternoon.
A "recent random spot test" revealed a problem with how some machines were calibrated, police said.
"As soon as the issue was discovered we made contact with Drager and sought urgent assurance that this problem will be fixed," Superintendent Steve Greally said.
Spot checks showed two of the devices tested did not meet required international and local calibration standards, Mr Greally said.
The Drager 7510s were "tested and calibrated correctly before rollout", police said in a statement.
Infringement notices, tickets or criminal charges laid as a result of Drager 7510 tests would be waived, police said.
There were 2900 other alcohol testing devices currently in use, and these had an "excellent reliability" record, police said.
In the meantime, officers would carry out breath tests using a different Drager model.
On its website, Drager described the 7510 model as a "robust handheld breath alcohol measuring device" designed for use in policing, commerce and industry.