The Russian, whom authorities have not publicly identified, was a member of the official Russian delegation to a meeting of the United Nations space committee in Vienna this month.
His arrest prompted a protest from Moscow, which said he was covered by diplomatic immunity.
The man was released after the UN's legal office on June 20 ruled he did indeed enjoy immunity during his stay in Austria.
"We are satisfied the Russian citizen, a member of an official delegation at the UN session devoted to space and detained on fabricated charges in Austria, was freed today," the Russian Foreign Ministry said in a statement. "He will soon return to his homeland."
(AFP, Reuters, RIA Novosti, mid.ru)