The Australian Federal Police (AFP) will not rule out charging journalists who published stories based on leaked, highly classified information.

The AFP raided the Canberra home of News Corp political journalist Annika Smethurst earlier this year, after a story she published last year regarding a proposal to expand the powers of the nation's intelligence agencies.

Less than 24 hours later, the AFP searched the ABC's Sydney headquarters over a separate story based on leaked information, which exposed allegations of misconduct by Australian special forces in Afghanistan.

The raids prompted the Government to request Parliament's intelligence and security committee examine whether there are appropriate protections for journalists and whistleblowers, or if too much ground has been ceded to national security.

During a hearing in Canberra this morning, Shadow Attorney-General Mark Dreyfus grilled police about one of the two cases.

"As we sit here, it remains the case that Annika Smethurst could be charged?" he asked.

"It remains the case that the investigation is ongoing, so I'm not drawing anyone in or out of who may have been determined, or who we may determine has committed a crime," Commissioner Andrew Colvin replied.

Media bosses appeared before the committee in Sydney yesterday, while the nation's law enforcement and security agencies are appearing in the nation's capital today.

Last Friday, Home Affairs Minister Peter Dutton issued a new directive to the AFP about how they should handle leak investigations that could result in media being drawn into inquiries.

It instructed the AFP to exhaust all other possible avenues of investigation, before involving journalists who published information.

Government departments and agencies asking the AFP to investigate leaks would also be required to explain exactly what damage has been caused by the information being in the public domain.

Under questioning from Labor home affairs spokeswoman Kristina Keneally, the AFP revealed it had prompted a review of all current leak investigations.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 24 seconds 24 s AFP Deputy Commissioner Neil Gaughan on the News Corp leak, suggesting it is a senior bureaucrat

"What we're currently doing is we've gone back to the referring agencies and asked them to specifically provide us with a harm statement of some depth," Deputy Commissioner Neil Gaughan responded.

Commissioner Colvin said he welcomed the direction being issued by the Minister, as it gave "certainty and clarity" to his officers.

The AFP chief, who is retiring at the end of September, said the AFP had received 75 referrals about classified leaks over the past five years, but only two had resulted in search warrants being used to search journalists' homes and offices.

His deputy explained how the case involving Ms Smethurst was serious enough to result in a warrant being issued.

"I think particularly with the one we're talking about, there is significant concern around the person who has provided, allegedly provided, the information to the journalist," Deputy Commissioner Gaughan said.

"Significant concern around where that person potentially sits within the bureaucracy."

His admission led Commissioner Colvin to whisper to him "just leave it at that".

Home Affairs boss accuses leaker of playing Canberra games

Home Affairs Secretary Mike Pezzullo says the bureaucrat who leaked to News Corp's Annika Smethurst should go to jail. ( ABC News: Ian Cutmore )

Secretary of the Home Affairs Department, Mike Pezzullo, appeared before the committee to launch a stinging criticism of the bureaucrat who leaked to Smethurst, arguing they should be sent to jail.

Of particular concern to Mr Pezzullo was the fact an image of the document appeared in the newspaper, alongside the article.

"This sort of information, combined with the fact that the reporting was so erroneous — but let's leave that to one side, no one is being investigated for poor journalism — but the fact that this document can be displayed in the Sunday Telegraph is just simply unacceptable," he told the committee.

The Home Affairs boss accused the leaker of breaking "two confidences".

"One is they leaked a top-secret document, and quite frankly subject to judicial process and fair process they should go to jail for that," he said.

"And secondly, it was designed to play into a Canberra game about which agency is asking other agencies to expand its powers and remits."

Deputy director of ASIO Heather Cook cautioned against any changes to the current laws around disclosure of classified information.

One of only a handful of the agency's officers who can be publicly identified, Ms Cook said Australian journalists were already being targeted by foreign spies.

"This practice is not novel or exaggerated," she said.

"Australian journalists have self reported to ASIO that foreign intelligence actors have sought to recruit them in order to gain access to privileged information or to senior officials."