Prime Minister Anthony Albanese has told Russia to "back off" after its embassy accused Australia's security chiefs of fuelling "anti-Russian paranoia" over an alleged spy couple accused of trying to access classified defence information.
Two Russian-born Australians have been arrested over an alleged spying scheme targeting the Defence Department, with authorities emphasising concerns over espionage and foreign interference.
Assuming the allegations are true, the spying may have been related to Australia's support for Ukraine or for nuclear submarine secrets passed on by the US under the AUKUS agreement.
The Russian Embassy in Canberra on Saturday accused Australia's federal police and spy agency chiefs of stoking anti-Russian paranoia.
"The press conference of AFP and ASIO chiefs on 12 July was clearly intended to launch another wave of anti-Russian paranoia in Australia," the embassy said in a statement.
"Theatrical tricks were used like talking to imaginary 'Russian spies' presumed to be all around."
But the prime minister declared Russia had no credibility and that it engaged in espionage around the world.
"Russia can get the message, back off," Mr Albanese said on Saturday.
"How about you get out of Ukraine and stop the illegal and immoral war that you're engaged in and how about you try to stop interfering in domestic affairs of other sovereign nations.
"This is a country that has no respect for international law, and they should be regarded with contempt, which is what I have for them."
The embassy has requested the situation and status of the arrested duo in writing and will consider appropriate measures of consular assistance.
Mr Albanese said he continued to have faith in the screening processes of Australia's national security agencies.
"The threats to us are nimble," he said.
"They're constantly trying to find ways to engage and to damage our national interest, and that's why our agencies ensure that they are constantly monitoring their performance."
Australia has become more attractive to Russian spy agencies as Canberra increases security collaboration with the United States after signing the AUKUS agreement, ANU National Security College senior adviser William Stoltz said.
"We have been a key part in the international sanctions regime against Russia as well, so they would be seeking to understand the military technology we have in development but maybe even other ways we are seeking to support Ukraine."
The fact army private Kira Korolev, 40, and her husband Igor, 62, have become the first people charged under a 2018 national security law showed the system was working, the national security expert told AAP.
The two Australians, who retain Russian passports, remain in police custody after neither applied for bail at a Brisbane court on Friday.
There was no ongoing threat, the Australian Federal Police said.
Police allege the army private visited Russia while on long-term leave in 2023 and coached her husband into accessing defence information through the computer.
Investigations into whether information was passed on are ongoing, with the prospect of charges being upgraded from preparing for espionage to an outright espionage offence.
The married couple arrived in Australia about 10 years ago before becoming citizens some years later.
Police are investigating whether their alleged links to Russia predate their arrival or they were turned after arriving in Australia.
Dr Stoltz said the pair would have been monitored for some time as there was a tendency within the intelligence community to "let things run for a while to fully identify the network the target is connected with and what information they are trying to obtain".
