The Age can reveal that the Andrews government has given police full power to deal "in-house" with any potential breaches of body-worn cameras, which have so far been sent to 8085 frontline police and protective services officers across the state.

But lawyers and human rights advocates fear that without independent sanctions and oversight, the system - designed to improve law enforcement and community safety - could easily be abused.

"There are no laws regarding when they have to be turned on, or when they have to be turned off," said Robinson Gill Lawyers principal solicitor Jeremy King, who has represented numerous victims of police brutality over the years. "Police have control of the entire system."

Critics are pushing for tougher safeguards - including state government penalties - for officers who misuse the devices.

It comes after a number of cases where investigations have been hampered because body-worn devices have not been activated at critical times.

One officer at an anti-mining protest used his body camera as a billboard for a sticker saying "EAD [Eat a Dick], Hippy".

Victorian Children's Commissioner Liana Buchanan was recently unable to fully examine alleged brutality by prison guards against youth offenders at the Grevillea Youth Justice Unit because "body-worn cameras were not operative during the time of the alleged assaults".

And in Queensland in 2016, the Supreme Court was forced to rule on claims of unlawful arrest involving a police officer whose body-worn camera was switched off during the period where consent to a search had allegedly been given.

Under the latest police guidelines, reviewed last month, officers are meant to turn on their cameras when "exercising their powers", such as when they make an arrest or execute a warrant.

But they ultimately have the discretion to decide if or when they choose to activate the device, in a bid to protect privacy or other sensitivities, and they do not need to inform people they are being filmed. If a recording is not made - or if the camera is stopped prematurely - the officer must simply make a note outlining the circumstances.

"At this point in time no disciplinary action has been taken regarding misuse of a body worn camera," a Victoria Police spokeswoman said.

The data recorded on the cameras is uploaded at the end of each shift to a secure storage system. However, the guidelines show that police can edit or redact the footage when preparing evidence "where absolutely necessary or required by law".

If someone making a complaint against an officer or a PSO asks to view the footage at their local police station, police can also limit access if they decide it may compromise an investigation or put a person in danger.

Police Association secretary Wayne Gatt said the current framework struck "the appropriate balance required to achieve positive benefits that support law enforcement and the community''.

"The community would not expect every single interaction police have with the public to be filmed, nor would they necessarily want it," he said.

And despite growing concerns, Police Minister Lisa Neville also defended the system, telling The Age: "We know the roll-out of body-worn cameras is already improving police and public interactions and leading to fewer complaints.''

Body-worn cameras were trialled in Victoria last year as a recommendation of the Family Violence Royal Commission, to make it easier for police to gather evidence. But they have gradually been expanded as a general feature of frontline policing, with 11,000 expected to be in operation by the end of the year.

But Gregor Husper, principal solicitor at the Police Accountability Project, argued that while the cameras have the potential to make police more accountable and boost community safety, "instead they have become another accountability failure".

Human Rights Law Centre director Ruth Barson said it was clear independent oversight was needed.

"If police are left to investigate their own, the result will be impunity."

- The Age