The Transport Accident Commission were the first to raise concerns to Victoria Police after they found an anomaly in data late last year, Mr Barrett said.
Mr Barrett said the audit found a suspicious number of breath tests were being conducted in quick succession.
But the faked tests were occurring one after the other.
Governance, controls and audit functions to support preliminary breath test (PBT) compliance and monitoring will be implemented immediately, police said.
But because the devices aren’t assigned to individual officers, it may be impossible to find out which police officers were falsifying the tests.
Up to 4 million alcohol tests are conducted on drivers every year, according to a previous police statement.
Victoria Police were planning to tell the public about the stuff-up early next week after gathering enough information to go public, Mr Barrett said. »