A BuzzFeed News request to see the secret Wickr chats between prime minister Malcolm Turnbull and former prime minister Kevin Rudd has been rejected.
The information commissioner ruled that the prime minister's office took reasonable steps to find the communications that had been deleted from the PM's phone.
In May 2016, it was revealed that Rudd had been talking to Turnbull on the Wickr encrypted messaging app about his bid to become the UN secretary-general. Rudd was seeking the Australian government's endorsement for his bid, and when Turnbull formally denied support, Rudd revealed in public letters that the two had been communicating on Wickr about the bid.
"You in fact sent me a message on your preferred Wickr system where you stated that you and the [foreign minister] were ‘as one’ in your support for my candidature," Rudd said in a letter to Turnbull in May 2016.
Since then, BuzzFeed News has been attempting to obtain the Wickr conversation using Australia's freedom of information law. Normally texts, emails and other communications between government ministers, their staff, and members of the public regarding government business are available under freedom of information law.
Wickr's platform operates on the basis of "data ephemerality" whereby the user can choose how long the message remains on the phone before being deleted.
The prime minister's office rejected the FOI request in late 2016, saying no record of the conversation existed, which indicated that the messages had been deleted by the time the FOI request was processed.
BuzzFeed News appealed to the Office of the Information Commissioner, Timothy Pilgrim, and in a decision released on Thursday, Pilgrim ruled that reasonable steps had been taken by the PM's office to attempt to find the messages, regardless of whether or not they still existed.
"The FOI Act provides individuals with a right to access documents that exist," PIlgrim said. "There is no right of access to documents that do not exist or cannot be found.
"Once a message has expired, the message would be securely destroyed from both the sender and recipient’s devices," he said.
"Accordingly, unless the sender or recipient has made a backup of the message, whether in an electronic or hardcopy format, prior to the expiration of the message, I am of the view that it would be highly unlikely that the message would continue to be stored on the device or in any other location."
It is outside the remit of the information commissioner to rule on whether such documents should be retained as part of the Commonwealth Archives Act.
It comes as the government is looking at introducing legislation that may attempt to force companies such as Wickr to provide access to messages sent over the platform to Australian law enforcement agencies.
Wickr CEO Joel Wallenstrom told BuzzFeed News last week that Wickr doesn't have access to the messages.
"We have no access to the actual messaging, so we are not technically capable of going beyond a certain boundary," he said.