A man thought to be a Russian diplomat is squatting in an embassy site amid a multi-million pound row with the Australian government.
It comes after the Australian government vetoed the plan to build a new Russian embassy in Canberra on security grounds.
After the government passed legislation, Russia is seemingly trying to overturn it in Australia’s highest court - kickstarting the bitter row.
His actions have been slammed by Australian Prime Minister Anthony Albanese who blasted a “bloke standing in the cold on a bit of grass in Canberra is not a threat to our national security.”
Mr Albanese added that he was confident the eviction would stand up to any legal challenge.
Parliament passed emergency legislation last week blocking Russia's lease on the largely empty block because the new embassy would have been too close to Parliament House.
A man has been living on the site in a portable building since Sunday, when passersby first saw Australian Federal Police outside the fenced block in Canberra's Yarralumla diplomatic precinct.
The Russian Embassy initially refused to comment on media reports that the man seen smoking cigarettes outside the building was a Russian diplomat.
The embassy also declined to explain why the man was on the site, saying in an email, "The Embassy does not comment (on) this."
Albanese said the issue would be "resolved," but did not explain how.
Speaking outside his office in Parliament House, he said: "Australia will stand up for our values and we will stand up for our national security,".
Russia later informed the country’s government that it intended to challenge the termination of the lease in the High Court on constitutional grounds, the Australian government said in a statement.
It added: "Russia's challenge to the validity of the law is not unexpected. This is part of the Russian playbook."
An injunction hearing has been listed for Monday, government officials said.
Australian National University international law expert Don Rothwell said occupying the site gave Russia no advantage in any legal challenge to the eviction.
"What they're doing is diplomatic civil disobedience in terms of indicating their displeasure with the action of the Australian government," Rothwell said.
He said Russia's only possible constitutional challenge would be to question the Australian government's power to overturn the decision by local Canberra authorities to issue the lease.
Or they could mount a challenge over the compensation offered for money already spent on construction and earthworks, Rothwell added.
Russia claims to have spent almost £3million on the site so far - completed works include fencing, and a single perimeter building.
If the alleged squatter is a diplomat he could claim diplomatic immunity if detained by police.
"That's the sort of scenario that I think the government would be keen to avoid," Rothwell said.
Albanese did not directly answer when asked if the government is considering revoking the man's diplomatic status.
"We're confident of our position that it will be resolved," he said.
Albanese said he was not concerned by the possibility of a Russian court challenge.
"We actually support the law. Russia has not been real good at the law lately," Albanese said, referring the Russian invasion of Ukraine.
Australian Federal Police declined to answer why the man had not been removed for trespassing.
Police advised reporters at the site on Friday not to cross the perimeter fence or gate which was chained and padlocked from the inside.
A hand occasionally shifting blinds was the only evidence anyone was inside the small cabin.
Russia last week accused Australia of "Russophobic hysteria" for cancelling the lease, which follows a deterioration in relations since the Ukraine war began last year.
In February, a newspaper reported that Australia had quietly expelled a large Russian spy ring whose members were posing as diplomats.
The spy ring included purported embassy and consular staff as well as other operatives using deep-cover identities, The Sydney Morning Herald reported, citing unidentified sources with knowledge of the operation.
The Australian Security Intelligence Organization, the nation's main domestic spy agency, revealed days earlier it had "detected and disrupted a major spy network." It has not named the country responsible.
The Russian Embassy has been contacted for comment.
