Four hundred of the devices were progressively rolled out by police during July. The fault was found in an internal random spot test. All Drager 7510 devices used by police were being recalled and tested, which was expected to take about a week, Mr Henderson said.
National manager of road policing Superintendent Steve Greally said while the issue was being investigated, police would continue to test drink drivers as normal using the Drager 6510 breath screening device, a previous model which was still in widespread use.
"Operationally, there will be no change to our continued enforcement of drink-drive offences, as testing machines in booze buses and stations are unaffected. This means anyone caught driving while impaired can expect to be dealt with in the same way," Mr Greally said. "As soon as the issue was discovered we made contact with Drager and sought urgent assurance that this problem will be fixed.
"In the meantime, as a precautionary step, we have removed all of the devices from service, which have now been sent to Drager for further testing to determine the exact nature and scale of the issue."