The body of Libya's former oil minister Shukri Ghanem, who had defected from Moamer Kadhafi's regime, was found Sunday in the Danube, Austrian police said in a statement.
No trace of violence was found on the body, police spokesman Roman Hahslinger said, adding that "it is possible that he felt unwell and fell into the water."
An autopsy will be carried out to determine the cause of death.
Earlier, APA news agency had reported that Ghanem was found dead in his apartment after having apparently suffered from a heart attack.
The news agency based its report on an Islamic expert Amer al-Bayati who was in turn citing Ghanem's family.
Ghanem, 69, who served as Libya's oil minister from 2006 to 2011, had fled to Vienna after his defection.
The funeral may be held in Libya, APA said, quoting Bayati.