A US defence official said on Thursday a US Predator drone along with a French fighter jet had attacked a convoy of vehicles in Libya that Paris believed was carrying Muammar Gaddafi.
French Defence Minister Gerard Longuet had earlier revealed that a French Mirage-2000 fired a warning shot at a column of several dozen vehicles fleeing Sirte.
The US defence official, who spoke on condition of anonymity, said the unmanned Predator aircraft had struck "the same convoy" but could not confirm that Gaddafi was in one of the vehicles.
Longuet told reporters in Paris that the convoy "was stopped from progressing as it sought to flee Sirte but was not destroyed by the French intervention."
Libyan fighters then intervened, destroying the vehicles, from which "they took out Colonel Gaddafi," he added.
The French warplane was sent to the area after news emerged of a large convoy of up to 80 vehicles trying to flee Sirte, he said.
After Libya's new leadership announced the death of Gaddafi, celebratory gunfire erupted across Tripoli on Thursday and jubilant crowds flooded onto the streets waving the red, black and green flag of the new regime.
The NATO-led air campaign was launched in March under a UN mandate to protect civilians from Gaddafi's forces trying to crush popular protests.