Austria has launched a probe into an army colonel suspected of spying for Russian Federation for decades, Chancellor Sebastian Kurz has said, the latest in a string of cases where Moscow has been accused of espionage in European Union states.
The relationship between the nations hit headlines in August when foreign minister Karin Kneissl danced with Mr Putin at her wedding.
The case has been referred to prosecutors, Kurz and Defence Minister Mario Kunasek said.
When questioned, the colonel said that the Russians had been interested in "weapons systems" as well as "the migration situation here in Austria".More news: Emma Stone's name change inspired by Emma 'Baby Spice' Bunton
Austria became aware of the case weeks ago thanks to a tip-off from an ally's intelligence service and "technical devices" including a laptop have been seized, Kunasek said.
He demanded "transparent information from the Russian side", saying that "the [Russian] ambassador - or rather, an authorised representative, because the ambassador is not in Austria now - was summoned to the Foreign Ministry".
The Russian Foreign Ministry summoned the Austrian ambassador on Friday to protest over "sensationalist media leak" about a former military officer accused of spying for Moscow, and expressed concern over damage to relations.
In Moscow, Russian Foreign Minister Sergey Lavrov accused Austria of "microphone diplomacy" for making what he called "public accusations and demanding an explanation over an issue we know nothing about".
According to Austrian media reports, the colonel was paid an equivalent of $340,000 for his services.More news: Death toll from Somalia hotel attack rises to 39
"Whether this was an isolated case can't be said at the moment", said Kunasek.
Austrian Foreign Minister Karin Kneissl said she canceled her visit to Russian Federation scheduled for December 2-3 due to the espionage case.
Austria is not a member of North Atlantic Treaty Organisation and sets great store by its status as a neutral country.
"If this suspicion is confirmed, it would be a serious burden on bilateral relations between Austria and..."
Austria is one of the few European countries that maintains close diplomatic contacts with Moscow despite Russia's actions in Ukraine, and even after the poisoning of ex-Russian spy Sergei Skripal and his daughter in Britain, which London has blamed on Russia. The FPO has a "co-operation pact" with Russia's governing United Russia party.More news: Pat Howard pushed out early as Cricket Australia purge continues