The Austria Press Agency reported that Salzburg prosecutors said Friday the man is suspected of having passed information about weapons systems and other matters to Russian military intelligence for about 25 years.
Prosecutors say the suspect's first contact with the GRU military intelligence service was in 1987. He allegedly started handing over information in 1993 and received hundreds of thousands of euros for his work.
Austria's government went public a year ago with the case against the 71-year-old, whose name hasn't been released, prompting Russian Foreign Minister Sergey Lavrov to accuse Vienna of "microphone diplomacy."
Austria traditionally has relatively warm relations with Russia.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.