The Commonwealth's decision not to charge a journalist who reported on alleged war crimes should be the catalyst for authorities to drop the prosecution of the man who blew the whistle, a lawyer for the former army officer says.
The Australian Federal Police issued a statement on Thursday afternoon, revealing it had "finalised an investigation into allegations that ABC journalist Daniel Oakes obtained classified information".
Mr Oakes was the author of a 2017 series of stories titled The Afghan Files, which covered allegations that Australian soldiers had engaged in the unlawful killings of unarmed civilians in Afghanistan.
The reporting was based on documents leaked by former army officer Major David McBride.
Police said they had submitted a brief of evidence to the Commonwealth Director of Public Prosecutions with a view to charging Mr Oakes.
The CDPP, according to police, found there were reasonable prospects of Mr Oakes being convicted of two out of three potential charges.
However, in determining whether to prosecute, consideration was given to "a range of public interest factors including the role of public interest journalism in Australia's democracy".
"The CDPP determined the public interest does not require a prosecution in the particular circumstances of this case," police said.
"As a result of this determination, the AFP has finalised its investigation into Mr Oakes."
The revelation prompted former senator Nick Xenophon, who is now a lawyer representing Mr McBride, to call for the charges against his client to be dropped.
Mr McBride has been charged with five offences including theft of Commonwealth property and the unauthorised disclosure of material to journalists Mr Oakes, Andrew Clark and Chris Masters.
He intends to fight the charges on legal grounds, and is scheduled to face a hearing next May to determine whether he has a public interest disclosure defence ahead of a potential criminal trial.
But Mr Xenophon said future proceedings should not be necessary.
"Logic, fairness, decency and, above all, the public interest demands that these charges against David McBride be dropped now," he said.
"If the CDPP considers that the role of public interest journalism, and its importance in our democracy, was a key factor in dropping the charges against Dan Oakes, then surely those considerations are even stronger in protecting the source for the story.
"After all, there would be no story without David McBride's bravery in providing it."
Mr Xenophon said Mr McBride had only gone to the media as a "last resort", having done "all that was possible" to address the relevant issues through official channels.
"The cruel irony is that if Major David McBride had been listened to years ago, potential war crimes could have been avoided," Mr Xenophon said.