ABC argues AFP raid 'legally unreasonable'

The national broadcaster has told a Sydney court it was "legally unreasonable" for federal police to seek a warrant to search its head office and for a registrar to grant it.

The Australian Federal Police raided the ABC's Ultimo offices in early June over 2017 news reports which revealed Australian defence personnel may have committed war crimes in Afghanistan.

The stories - dubbed the "Afghan files" - were based on leaked Defence papers.

Lawyers acting for the ABC on Friday told the Federal Court it was "legally unreasonable" for authorities to seek the search warrant and for local court registrar Martin Kane to grant it.

The broadcaster wants the warrant retracted and their seized files returned.

It argues the conditions of the warrant were too broad and "materially misstate the terms of the suspected offences".

The ABC also contends that journalistic privilege and the right to protect sources should endure despite whistleblower David McBride admitting publicly that he leaked the Afghan files.

"The privilege of the journalist is that of the journalist, not the source itself," ABC barrister Matt Collins QC said on Friday.

"No such statement (confirming the source of the leak) has ever been made by the ABC. Mr McBride may have said such things but the ABC has not."

The ABC is relying on both the public interest in investigative journalism and the implied constitutional freedom of political discussion.

Lawyers for the AFP, however, argued it was "plainly wrong" to suggest the registrar should have declined to issue the warrant.

Federal officers in early June took possession of some 100 documents on national security grounds and transferred the contents to USB sticks.

To issue a warrant, a court officer must state the warrant's related offences, and be satisfied there are reasonable grounds for suspecting the relevant material is, or soon will be, at the premises.

The ABC argues Mr Kane didn't consider those requirements but the AFP disagrees.

"(The ABC says) any reasonable person in the position of the registrar would have declined to issue the warrant ... we say that's plainly wrong," AFP barrister Neil Williams SC said.

"The warrant itself (reflects) that the first respondent (Mr Kane) is satisfied by the information on oath."

Justice Wendy Abraham listed the case for further argument on August 19.

The AFP has made an undertaking it will not access the seized material until the resolution of the ABC's application.