French warplanes identified and "stopped" a convoy of vehicles carrying Muammar Gaddafi before he was killed in clashes in Libya, French Defence Minister Gerard Longuet said.

The convoy of several dozen vehicles "was stopped from progressing as it sought to flee Sirte but was not destroyed by the French intervention," Longuet told journalists.

Libyan fighters then intervened, destroying the vehicles, from which "they took out Colonel Gaddafi," he added.

He said French planes were sent to the area after news emerged of a large convoy of up to 80 vehicles trying to flee Sirte.

He said a French Mirage-2000 "was informed by the integrated general staff (of NATO) of the need for an intervention to prevent this column from advancing."

He said the plane then intervened and managed to separate some vehicles from the convoy, which were then confronted by fighters from Libya's National Transitional Council.

"In these clashes, vehicles were destroyed, people were wounded and killed and it was among them that... Gaddafi was a part," he said.