A US drone and a French fighter jet fired shots on a convoy believed to be carrying Moamer Gaddafi shortly before his death, a defence source told Fox News on Thursday.
The convoy of around 80 vehicles was seeking to leave Sirte when it came under fire, dpa reported.
A French source had said that the convoy was not hit in the strike, but that fighters affiliated with Libya's transitional forces later intercepted Gaddafi's vehicle.
The former strongman died of serious gunshot injuries to the head and stomach, inflicted during his capture, according to medical sources in Libya.
US State Department spokesman Mark Toner said the details of Gaddafi's death remained unclear.