Taskforce Deliver, led by former chief commission Neil Comrie, started investigating in June 2018 after a person made an anonymous complaint alleging members of Victoria Police falsified PBT numbers.

The Taskforce found police officers were falsifying tests by either blowing through the tube to record a test or covering the ends of the tube to change the air pressure, which the instrument would register as a test.

The report said there was also "anecdotal information" that showed a device could be held outside the window of a moving vehicle and the rush of air was recorded as a test.

Read more: Victorian police fake alcohol breath tests

The latest report followed other investigations into falsified PBTs records in 1996, 1999, 2004, and 2014.

In 1996, officers in regional Victoria - specifically Bendigo, St Arnaud, Echuca and Shepparton - were investigated amid reports of false PBT reports.

A total of 40 members ranging in rank from constable to sergeant were interviewed regarding disgraceful conduct.

It was alleged that between February and September 1996, they had falsely claimed to have undertaken PBTs by recording registration numbers of vehicles when the drivers were not tested.

That investigation resulted in six members being admonished.

While the 1996 investigation related to the falsification of records rather than falsification through self-testing, Taskforce Deliver's report indicated those earlier indiscretions were "potentially an indicator of a systemic problem that required a more substantial investigation".

Read more: Breath test falisification widespread: report

The report also noted the previous investigations were "generally treated as isolated incidents" and therefore, "the behaviour continued and became wide-spread common practice".

It also noted that a major cause of PBT falsification was the introduction of number-based targets, which many members of the police force viewed as "meaningless and unachievable". Victoria Police were expected to conduct 4.5 million preliminary breath tests in 2017.

Taskforce Deliver has made 23 recommendations following the report, which include daily audits of PBTs and replacing current PBT devices with new devices that include "major advancements in technology".

Victoria Police said it has accepted all of the recommendations and will "continue to work with government, the TAC and other road safety partners to review current arrangements and strategies for PBTs and to ensure the integrity of Victoria's roadside testing regime".

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