Queensland police will not examine the legality of a local council’s audio surveillance scheme, despite concerns the recordings could breach privacy laws and be inadmissible in court.

Moreton Bay regional council last week switched on microphones on more than 330 CCTV cameras to record public conversations, citing the need to provide police with audio to accompany footage requested for criminal investigations.

The roll out of what is believed to be the first local government-run audio surveillance scheme in Australia has prompted an investigation by the state’s privacy commissioner, who suspects it could be unlawful.

The commissioner, Phil Green, who has rejected claims he approved the scheme, is reviewing its compliance with the state’s Information Privacy Act.

Guardian Australia understands Green has asked the council for more information on its data security but is yet to be convinced its collection of private conversations is lawful. But a spokeswoman for Queensland police told Guardian Australia there was no plan to investigate whether the scheme was also a breach of the Invasion of Privacy Act.

Green, the Queensland Law Society and the Queensland Council for Civil Liberties have all raised concerns the scheme violates that act, which is administered by police.

Bill Potts, a spokesman for the law society, said if court cases relied on recordings shown to be obtained illegally “then it’s inadmissible and the much vaunted reason for doing it is nullified”.

The mayor of Ipswich, Paul Pisasale, rejected the audio surveillance scheme as “pushing Big Brother too far”. Pisasale said adding audio to CCTV did not “add to the value of a safe city”.

“I don’t understand why it would add value to a court case, and unfortunately it’d be picking up everybody’s voice, so it means that people couldn’t have a normal conversation in a public place,” Pisasale said. “I can understand people feeling that it is an invasion of privacy.

“Bugging places – that’s what it is – in public spaces, you don’t need it. It’s a no-brainer.”

A spokeswoman for the Queensland police minister, Mark Ryan, said his office had been assured by police they could not investigate without a complaint from a member of the public.

Potts, a prominent criminal lawyer, said that was not true.

“Seriously, police have a perfect right to investigate offences which they themselves see occurring – in murder there’s no complaint,” he said. “The council has announced they’ve set up [this] system … the police are aware of that. Why will they do nothing?

“It’s a bit like Inspector Clouseau not seeing the end of his nose. It’s there. It’s sticking out in front of them. What more do they actually need?”

The Moreton Bay council, north of Brisbane, which plans to extend audio across its network of 874 cameras, may face pressure to abandon the scheme if the commissioner rules it unlawful. Green may also direct the council to stop recording audio by issuing a compliance notice.

His findings, which he will report to the parliamentary committee on legal affairs and community safety, are likely to set a precedent for other councils considering the scheme.

The police spokeswoman said officers in the Moreton Bay region had been consulted by the council on the audio recording scheme, but did not request it.

A spokeswoman for the council said it was “satisfied its use of the CCTV footage and audio is consistent with its obligations under the Information Privacy Act”.

But she refused to say what the source of its legal advice was, or whether it was also satisfied it complied with the Invasion of Privacy Act.

“Council will continue to work together with the office of the information commissioner to ensure its CCTV network operates in accordance with the act and protects personal information of the community,” the spokeswoman said.

Last week Green said the council’s willingness to cooperate with his office on the issue was “a positive step in the process”.

“While I have concerns about the upgraded cameras’ ability to record audio, it’s vital to have all the facts before proceeding further,” he said.

Potts has repeatedly called on the attorney-general, Yvette D’Ath, and Ryan to say whether they condoned the council’s recordings of allegedly private conversations in public.

A spokeswoman for D’Ath said the Department of Justice and Attorney General “was not consulted on this matter” but that it did not “provide legal advice”.

“The attorney general understands this matter is being examined by the office of the information commissioner, which is an independent statutory body,” the spokeswoman said.

Section 43 of the Invasion of Privacy Act states that a person, or an executive officer of a corporation, faces up to two years jail if found guilty of recording a private conversation to which they are not party.

Exceptions include listening devices worn by police or commonwealth agents with warrants.