The warrant used by Australian Federal Police officers to search the home of News Corp journalist Annika Smethurst last year has been thrown out by the High Court.

Ms Smethurst’s home was raided after the Sunday Telegraph published a story she wrote on plans to expand the powers of the Australian Signals Directorate.

More than a year after the story went to print, the AFP obtained a search warrant for a range of general items belonging to Ms Smethurst and an order she provide her phone password.

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The raid sparked a national debate about press freedom, which intensified when AFP officers searched the ABC’s Sydney headquarters over a different story the same week.

The High Court found the warrant was invalid as it misstated the relevant law and failed to specify the offence being investigated.

As a result, the court did not consider whether the raid impacted freedom of political communication.

The court ordered the AFP pay the costs of Ms Smethurst and News Corp.

AFP allowed to keep seized materials

Lawyers for Ms Smethurst, and her employer News Corp, argued the court should issue an injunction requiring the AFP to hand back the seized materials or destroy any copies.

While the court was unanimous in quashing the warrant, it was divided over what should happen to the material seized.

Political journalists campaign for the public’s right to know outside Parliament House on 21 October 2019. Photo: ABC News/Toby Hunt

The data taken from Ms Smethurst’s phone was identified through specific word searches for items including mentions of the ASD and story pitches.

The Commonwealth had asked the High Court to find it should be allowed to keep the material, even if it was obtained illegally.

While three judges said they thought the material should not be kept by police, the majority of the court declined to make an order, meaning police could keep the material for any future possible prosecution related to the case.

The decision opens up the issue to further legal argument.

If the case was ever to come to trial, lawyers could argue the data was not able to be used as evidence because the warrant had been thrown out by the highest legal authority in the land.

But no trial is on the horizon, and Attorney-General Christian Porter has said any decision on prosecuting journalists will need to be signed off by him.

A spokesman for the AFP said it was considering the decision and would “act in accordance with the ruling”.