"The espionage is unacceptable. This case should, of course, be thoroughly probed," Van der Bellen said in an interview with the Osterreich daily newspaper.
Austrian Foreign Minister Karin Kneissl has canceled her visit to Russia and summoned the Russian charge d’affaires amid the espionage scandal.
Russian Foreign Minister Sergey Lavrov, in his turn, said he was unpleasantly surprised by the situation. Austrian Ambassador to Russia Johannes Aigner was also summoned to the Foreign Ministry to discuss it on Friday.
Moreover, Moscow expressed protest to Aigner over the accusations that a retired Austrian colonel had been involved in intelligence activities allegedly in favor of Russia.