Drunk drivers across the country may get off scot-free with a breathalyser machine fault causing police to drop charges and tickets.
Police have recalled all 400 of their Drager 7510 portable breath test devices - which have been in use since July - after several failed random tests.
A calibration error means any tickets issued by a dodgy device - about 80 - could be challenged in court and police have decided to drop them.
"While the devices that have failed have only done so by a very small margin, for the avoidance of any doubt we have decided to waive any infringements or charges that may have resulted from them," Superintendent Steve Greally.
He said the complete withdrawal was a precautionary step while the manufacturer of the device worked to fix the error and work out which machines are faulty.
But drunk drivers won't be getting off lightly in the mean time, with officers still continuing to use an older version of the breathalyser.
"Operationally, there will be no change to our continued enforcement of drink drive offences, as testing machines in booze buses and stations are unaffected," Supt Greally said.
He said any drivers getting off because of the small error should "consider themselves very lucky".
The devices have been used mainly in rural areas.