The High Court has found that a search warrant used by the AFP to raid journalist Annika Smethurst was invalid.

The News Corp Australia report has her apartment raided in 2019 over stories that revealed secret plans to expand the government's spying powers.

But the warrant used at the time was not drafted precisely enough and should be quashed, the High Court has now found.

However, judges could not agree on whether the Australian Federal Police should have to destroy material seized during the search.

Ms Smethurst was forced to unlock her phone so that police could copy information from the device to a USB.

It is not known what data is stored on the USB, but two judged believed it should have been destroyed. Other judges determined that the data could disclose criminal conduct, and that no specific right would be protected by destroying it.

AFP Commissioner Reece Kershaw says he is waiting for legal advice on what to do with the data.

“At this moment it's quarantined, investigators are not able to look at that,” he said.         

News Corp wants the government to give up.

“Annika Smethurst should not be prosecuted for simply doing her job as a journalist to rightly inform Australians on serious matters of public interest,” the media company's executive chairman Michael Miller said.

“It's time for the federal government to bring this sorry mess to a prompt end. It's time to end Annika's ordeal.”

Shadow attorney-general Mark Dreyfus is concerned that the police will use the data.

“That's something the government can now put to rest. It should rule out prosecution of Ms Smethurst or any other journalist for simply doing their job,” he said.

The court was called to consider the specific wording of warrant, not the broader issue of whether the raid infringed on implied freedom of political communication.

The media union says that if police do not have to destroy the data, then that means “there is no protection for public-interest journalism in Australia”.