According to reports the Austrian police has confirmed the death and said the corpse of 69-year-old Shukri Ghanem was found floating in the river early in the morning.
Police spokesman Roman Hahslinger said that the body showed no external signs of violence.
“It is possible that he felt unwell and fell into the water,” he said.
Ghanem is a former Libyan premier who last served as his country’s oil minister until 2011. He left Libya in June as civil war was raging in the country, and subsequently announced that he would support the rebels fighting Gadhafi’s troops.