The body of Libya's former Oil Minister Shukri Ghanem has been found in the Danube River, Austrian police say.
A spokesman said there were no signs of violence to Mr Ghanem's body, which was in the river that flows through Vienna.
The former prime minister, 69, worked as a consultant for a Vienna-based company. He apparently left his home early on Sunday, police said.
Mr Ghanem defected from Libya as the country was engulfed in the uprising against Col Muammar Gaddafi last year.
At the time, he criticised the bloodshed in Libya, saying that the situation had become "unbearable", making his position untenable.
He served as Libyan prime minister from 2003 to 2006 and then as oil minister until 2011.Post-mortem examination
A passer-by reported seeing the body under a bridge near a popular recreation ground in Vienna.
Police spokesman Roman Hahslinger said Mr Ghanem was dressed when he was found but had no personal identification documents on him, with the exception of one naming the company he was working for. An employee of the company had identified him, the spokesman said.
Mr Hahslinger said: "There would be no signs of violence if someone pushed him in. But it's also possible that he became ill and fell into the water."
A post-mortem examination has been ordered for the coming days.
The former prime minister is understood to have been in Europe since his defection last June, and to have had family in Vienna.
His connection to the city dates back to the time he worked at the Organisation of the Petroleum Exporting Countries (Opec) - a forum he later visited regularly as Libyan oil minister.
The Libyan uprising ended in October last year with the killing of Col Gaddafi.
In June Libya will hold elections to a constituent assembly, whose first task will be to draw up a constitution.