Government officials have long been adamant there was never a plan to spy on Australians. Rather, the potential expansion of the ASD's role involved using the agency's capabilities to disrupt in the systems of cyber-enabled criminals such as paedophile rings and organised crime gangs in Australia. It would also have allowed the ASD to better protect critical infrastructure from hacking. Loading But the change would nonetheless have meant the ASD was carrying out domestic activities in ways it had not been previously. Before, the ASD had been used to smash computer networks of overseas criminals if having them arrested was not an option. If found and convicted, the source of the leak faces a jail sentence of up to two years. The AFP said in a statement on Wednesday that they were investigating breaches of the Crimes Act, under which it is an offence for Commonwealth officials to disclose information which "it is his or her duty not to disclose".

But they added that the alleged crime happened before new secrecy laws were created last year in the government's espionage and foreign interference laws. Loading Under those new laws, a journalist and publisher in the same situation could be liable for prosecution but could use the defence that they reasonably believed they were reporting a matter of public interest. University of NSW law professor George Williams said: "There are a number of areas where journalists can get caught, because there aren't defences for what we would consider reasonable journalistic conduct." It is understood neither Mr Turnbull and the then defence minister, Marise Payne, knew of the discussions about the ASD's role before Smethurst's story was published in April 2018.

Mr Turnbull contacted ASD director-general Mike Burgess after the story went public asking for an explanation. Sources said Mr Turnbull later told the national security committee of cabinet that he would not support a broad domestic expansion of the ASD's activities out of an "abundance of caution". Home Affairs Minister Peter Dutton told The Sydney Morning Herald and The Age in an interview in December 2017 that he would like the ASD to have "a greater domestic focus than they've had in the past". Australian Federal Police raided the home of News Corp journalist Annika Smethurst over the leak of top secret information. Credit:ninevms Traditionally the ASD - part of the Defence portfolio - has had an overwhelmingly overseas focus, gathering electronic or "signals" intelligence from around the world including to support Australian Defence Force operations. It also helps secure government computer networks.