Former Libyan oil minister Shukri Ghanem, whose body was found floating Sunday in the Danube river, died from drowning, Austrian police said.

Autopsy results on Ghanem's corpse showed no signs of violence, police spokesman Roman Hahslinger said Monday. The body was found in a section of the Danube that runs through Vienna close to where he had a residence.

Ghanem last year announced he was abandoning Gadhafi's regime to support the rebels who ultimately toppled the dictator. He was a former Libyan premier who last served as his country's oil minister until his 2011 defection.

He left Libya for Tunisia and then Europe in June as insurgents were pushing to topple Gadhafi. In Vienna, he worked as a consultant for an Austrian company.

Considered a member of Gadhafi's inner circle until his defection, he insisted that Libya bore no responsibility for the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, which killed 270 people.

Hahslinger suggested the death may have been an accident and that Ghanem, 69, had complained to his daughter late Saturday that he was not feeling well. No suicide note has been found and there is no evidence Ghanem was under threat, Hahslinger said.

The results of toxicological tests are expected later this week.