Federal police wanted to fingerprint two ABC journalists involved in a series of stories about Australia’s special forces allegedly carrying out unlawful killings in Afghanistan.

The letter from the Australian federal police to journalists Dan Oakes and Sam Clark was emailed on 1 April – two months before AFP officers raided the ABC’s Sydney headquarters seeking leaked documents relating to the stories.

The ABC said the email stated the AFP was “requesting your consent to a forensic procedure being the copying of your finger and palm prints”, with the two journalists being suspects in relation to three alleged offences.

Veteran ABC journalist John Lyons also reported that police were also poised to raid the headquarters of News Corp, in Holt Street, Sydney, but backed off following the backlash over the raids on the ABC and journalist Annika Smethurst.

#Breaking: how the AFP told 2 senior journalists they wanted to “copy your finger and palm prints” and how the AFP was poised the next day to raid Holt St, the Sydney HQ of News Corp, but pulled out because of the backlash against the two other raids they did in previous 24 hours https://t.co/kdajU1UkH5 — John Lyons (@TheLyonsDen) July 15, 2019

The ABC declined to comment further on Monday, beyond confirming the AFP request had been received.

The revelation followed a report in the Sydney Morning Herald that said the AFP had sought from the travel details of Oakes from Qantas.

The federal attorney general, Christian Porter, has previously said journalists were not the subject of “present investigations” and expressed his reluctance to authorise the prosecution of journalists. But he has since distanced himself from those comments, saying they were made with the limited information available to him at the time.

The home affairs minister, Peter Dutton, was last week pressed by media chiefs to drop any police action against ABC journalists. But he said on Friday that no one was above the law.

“If you’ve got top secret documents and they’ve been leaked, it is an offence under the law,” Dutton said on Channel Nine. “Nobody is above the law and the police have a job to do under the law.”

The ABC’s managing director, David Anderson, has asked for the investigation to be dropped and is pursuing legal action to declare the search warrant involved in the raid invalid.

It is also seeking a permanent injunction stopping the AFP accessing the electronic files removed from Ultimo on a sealed USB stick.

Former military lawyer David McBride has been committed to stand trial charged with theft of commonwealth property, three counts of breaching the Defence Act and unauthorised disclosure of information.

The Australian Federal Police Association in June backed the professionalism and integrity of the officers involved in carrying out the search warrant.

But the raids on the ABC have prompted worldwide condemnation. Last week, human rights lawyer Amal Clooney described the raids as an example of how limits on press freedom were also occurring in democratic nations.

“What happens in a country like Australia or the UK or the US will be looked at by every other leader in the world and potentially be used as an excuse to clamp down even further on journalists,” she said.

The parliamentary joint committee on intelligence and security has begun an inquiry into the impact of the exercise of law enforcement and intelligence powers on the freedom of the press.

Submissions to the inquiry close on 26 July and it is due to report in October.

McBride is one of a series of whistleblowers currently facing imprisonment for their actions. Intelligence officer Witness K and his lawyer Bernard Collaery are facing jail time for their actions in helping expose an illegal spy operation on Timor-Leste, while tax office whistleblower Richard Boyle is in court for speaking out about the aggressive tactics used against small businesses and individual taxpayers.