News Corp's report included details from a top secret internal document proposing new abilities to "proactively disrupt and covertly remove" onshore threats by "hacking into critical ­infrastructure". The federal police confirmed the execution of a search warrant on Tuesday as part of an "investigation into the alleged unauthorised disclosure of national security information". In a statement, the police said they would allege the disclosure of "these specific documents undermines Australia's national security". "No arrests are expected today as a result of this activity," the statement said. In an updated statement, police said the warrant was in relation to "the alleged publishing of information classified as an official secret, which is an extremely serious matter that has the potential to undermine Australia’s national security".

Loading The police arrived at Smethurst's home at about 9am and stayed until 4.30pm. A spokesperson for News Corp Australia said the police raid was a "dangerous act of intimidation" and would have a chilling effect on public interest journalism. "The raid was outrageous and heavy-handed," the spokesperson said in a statement. "News Corp Australia has expressed the most serious concerns about the willingness of governments to undermine the Australian public's right to know about important decisions governments are making that can and will impact ordinary Australian citizens.

"What's gone on this morning sends clear and dangerous signals to journalists and newsrooms across Australia." 2GB radio host Ben Fordham also revealed on Tuesday that he has been contacted by Home Affairs this week about his reporting, with the department investigating how he obtained "highly confidential" information about asylum seeker vessels. Smethurst's story reported the top secret proposal as one that would for the first time allow the ASD to target Australians, as opposed to enemies on foreign soil. The use of the powers would be subject to approval from the defence and home affairs ministers. Government sources were quoted as calling the proposed powers a "political power grab" that had concerned some insiders. The secretaries of the Home Affairs and Defence departments, Michael Pezzullo and Greg Moriarty, and the director-general of ASD, Mike Burgess, hit back at the story, saying there was "no proposal to increase the ASD's powers to collect intelligence on Australians or to covertly access their private data".