Austrian authorities have questioned a recently retired senior military officer on suspicion of spying for Russia for decades, and demanded an explanation from Moscow, Chancellor Sebastian Kurz said on Friday.
Foreign Minister Karin Kneissl, who danced with Russian President Vladimir Putin at her wedding in August, has cancelled a planned trip to Moscow over the case, which involves a colonel whose spying activities are believed to have begun in the 1990s.
The case has been referred to prosecutors, Kurz and Defence Minister Mario Kunasek said.
Issues of interest to the officer or his alleged handlers included weapons systems and migration, Kunasek said, adding that it was not clear whether the case was an isolated one.
Without naming the suspect, Kurz told reporters: "If the suspicion is confirmed, such cases… do not improve relations between Russia and the European Union."
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.
"For the moment we are demanding transparent information from the Russian side," Kurz said.
In the ambassador's absence, the Russian charge d'affaires had been summoned to the Foreign Ministry "and anything further we will discuss with our European partners," the chancellor said.