The Australian federal police commissioner has not ruled out prosecuting the News Corp journalist Annika Smethurst, telling parliament’s intelligence and security committee the investigation into leaked material remains ongoing.

Asked whether it remained the case that Smethurst, who was the subject of a controversial police raid this year, could ultimately be charged, the commissioner, Andrew Colvin, replied: “It remains the case that the investigation is ongoing.”

The deputy AFP commissioner Neil Gaughan told the committee: “That is a live investigation.” Gaughan also signalled to the committee police that were hunting for the source. He said there was “significant” concern about where the person who had allegedly provided the material “potentially sits in the bureaucracy”.

The secretary of the home affairs department, Mike Pezzullo, told the committee the AFP had a suspect and was “closing in” and he declared that, subject to proper judicial processes, the person who engaged in unauthorised disclosure should “go to jail”.

ABC tells court AFP search warrant for raids was 'legally unreasonable' Read more

In April 2018 Smethurst reported that the heads of the defence and home affairs ministries had discussed draconian new powers to allow the Australian Signals Directorate to spy on Australian citizens for the first time. According to the story, spies would be allowed to secretly access emails, bank accounts and text messages with approval from the defence and home affairs ministers.

More than a year after publication, in June 2019, police raided Smethurst’s Canberra home. The warrant indicated police were investigating the “alleged publishing of information classified as an official secret” which they said had the potential to undermine Australia’s national security.

The raid has infuriated News Corp, and has prompted a rare show of unity on the part of Australian media organisations, with major companies declaring that various tranches of legislation expanding police and security agency powers have diminished press freedom.

On Tuesday senior managers from Nine, the ABC, News Corp, Free TV Australia, the Sydney Morning Herald and the Age fronted the intelligence committee to argue that the national security regime needed to be better balanced against the public’s right to know.

News Corp and the ABC, which was the subject of a separate police raid in June, have launched court proceedings to set aside the search warrants.