Prime Minister Scott Morrison has dismissed concerns about a police raid on a News Corp journalist's home more than a year after a story she reported.

Key points: Scott Morrison says Federal Police followed the law when they raided a journalist's Canberra home

Scott Morrison says Federal Police followed the law when they raided a journalist's Canberra home AFP officers spent seven hours in Annika Smethurst's home more than a year after the publication of a story she reported

AFP officers spent seven hours in Annika Smethurst's home more than a year after the publication of a story she reported The story alleged the government was considering giving spy agencies greater domestic surveillance powers

Australian Federal Police (AFP) officers spent hours raiding Annika Smethurst's Canberra home yesterday, alleging there had been an unauthorised leak of "national security information" in a story she wrote in April 2018.

The AFP said the story included information classified as an official secret.

The Prime Minister — who is in London for his first meeting with the Queen — initially said the raid was an ongoing matter for the AFP and police were better placed to comment.

But when asked if he was concerned at a journalist's home being raided, the Prime Minister said "it never troubles me that our laws are being upheld".

Smethurst's story, which included photographs of government documents, said the Home Affairs and Defence departments were considering giving spy agencies greater surveillance powers.

The story alleged new powers, if adopted, would go to the Australian Signals Directorate (ASD) to secretly access bank records, emails and text messages without leaving a trace.

Federal Police raided News Corp journalist Annika Smethurst's house following a story she wrote a year ago. ( ABC News )

Attorney-General Christian Porter said suggestions the Government had orchestrated the raid were "utterly untrue".

He said the AFP might have told the Home Affairs Minister Peter Dutton, who was in Sri Lanka when the raid occurred, about the raid prior to it happening.

Mr Porter described the raid as an information-gathering exercise for the AFP.

"The investigation is not about the journalist per se. It's about the disclosure of information," the Attorney-General said.

The Defence Department referred the leak to the AFP on April 29, 2018, the same day News Corp published the story.

Mr Morrison refused to comment on whether he supported the proposal Home Affairs and Defence bureaucrats were alleged to be discussing in Smethurst's story.

He said Federal Police followed the law when they carried out the raid, arguing it was not an attack on free press.

"Australia believes strongly in the freedom of the press and we have clear rules and protections for freedom of the press," Mr Morrison said.

"There are also clear rules protecting Australia's national security and everybody should operate in accordance with all of those laws passed by our Parliament.

"I support the powers that the agencies have under our laws."

ASD collects and assesses foreign intelligence information before passing it on to Australia's domestic and foreign spy agencies.

The agency does not collect information on Australian citizens, but some senior public servants want to change that.

Opposition and crossbench want answers

Deputy Labor leader Richard Marles wants Mr Dutton to explain why the raid was necessary.

He said it was a significant development for police to raid a journalist's home in a nation that valued press freedoms.

"I think it's important for the Minister to give an explanation to the Australian people about what occurred here," Mr Marles said.

A South Australian crossbench senator, who would play a crucial role in helping the Government pass legislation in the Upper House, said authorities had serious questions to answer after the raid.

Centre Alliance senator Rex Patrick said Smethurst was simply performing her public duty.

"There are serious questions about the timing of the raid, why the raid only occurred at her home and indeed what steps had been taken prior to the raid being conducted," he said.

Senator Patrick has been a vocal critic of whistleblower protections during his time in the Federal Parliament.

He said he was concerned AFP officers spent seven hours in Smethurst's home rather than her press gallery office.