Act giving AFP powers to monitor An0m devices did not become law until after FBI operation began

The Australian federal police have clarified the legal basis for a wide-ranging operation that ensnared hundreds of people using compromised encrypted devices developed by an FBI informant.

The An0m devices were released in October 2018 by a convicted narcotics importer who was working for the FBI.

The FBI spent almost three years monitoring the content of messages sent using the platform with the assistance of the Australian federal police, until it was shut down on Tuesday and the infiltration was revealed.

AFP commissioner Reece Kershaw said at the time that the operation was legally authorised under the Telecommunications and Other Legislation Amendment (Tola) Act, along with a legal authorisation from the FBI.

But the Tola – which has been criticised for being too complex and providing extraordinary powers to law enforcement and intelligence bodies – did not come into law until two months after the first An0m devices were released into Australia as part of an FBI “beta test” in October 2018.

An AFP spokesperson said on Thursday that the Tola was among “a range of legislative provisions” used to facilitate the operation, codenamed Ironside.

“All warrants in Operation Ironside were issued by independent issuing authorities.

“There are provisions in commonwealth legislation which prevent the AFP from confirming the details of the legislative provisions relied upon until these matters are lawfully disclosed in open court.

“The AFP will elaborate further when it is appropriate and lawful to do so.”

The AFP added that it used “appropriate legislative powers to collect evidence of alleged serious criminal offending”, used a full-time, dedicated compliance coordinator and local compliance experts in every state, and engaged with the commonwealth ombudsman.

More than 12,000 devices were sold to criminal syndicates operating in about 100 countries who sent 27m messages before the network was shut down.

Seventeen people across the world have been charged in an FBI indictment, including Turkish citizen Hakan Ayik, who previously lived in Australia.

The men have been charged in the US with violating the Racketeer Influenced and Corrupt Organizations (Rico) Act and face a maximum penalty of 20 years in prison.

The AFP spokesperson was unable to clarify the status of Domenico Catanzariti, an Adelaide man who was taken into custody in the past week.

The FBI alleges Catanzariti was the only Australian-based administrator of the An0m network in an indictment that was unsealed earlier this week.

But the AFP were unable to confirm where Catanzariti was being held, whether he had faced court, if he would be subject to criminal charges in Australia, or whether US authorities had requested his extradition. The FBI and the Australian attorney general, Michaelia Cash, were contacted for comment.

Relatives and colleagues of Catanzariti who were contacted by Guardian Australia either did not respond or declined to comment. It is unclear who is acting as Catanzariti’s lawyer.

Craig Caldicott, the South Australia law society criminal law committee chair, is representing several people charged after evidence was gathered about their alleged offending under Operation Ironside.

He said he remained concerned about the legal basis for each individual case, despite the assurances of the AFP.

These concerns include whether a warrant for each of the more than 1,600 An0m devices in Australia was authorised by an officer ranked as a superintendent or above, as Caldicott believes is required.

An FBI informant providing devices that handed intelligence to the AFP that was then used for arrests and charges by state police presented a series of potential jurisdictional issues, Caldicott said.

He also believes that some of the issues in a successful 1995 high court appeal brought by John Anthony Ridgeway, who had been convicted of trafficking heroin after an AFP operation, could apply to those charged under Ironside.

In that case, the court found that the unlawful conduct of AFP officers prior to the alleged trafficking meant the conviction should be quashed.

“The AFP have got a major problem I think and haven’t realised it yet,” he said. “There’s going to be all sorts of issues over who was responsible for what.”