Nato forces designated Gaddafi as a military target after the former Libyan leader’s forces started firing on civilians as they tried to escape Sirte in a convoy of up to 100 vehicles.
It is understood that RAF Tornados were patrolling over Sirte at the time of the escape attempt but were not directly involved in the operation.
Gaddafi had been under surveillance by Nato forces for the past week after an intelligence breakthrough allowed them to pinpoint his location.
An American drone and an array of Nato eavesdropping aircraft had been trained on his Sirte stronghold to ensure he could not escape.
“US Predators and French drones have been staking out the centre of Sirte for several weeks trying to monitor what’s going on on the battlefield,” said an intelligence source. “They built up a normal pattern of life picture so that when something unusual happened this morning such as a large group of vehicles gathering together, that came across as highly unusual activity and the decision was taken to follow them and prosecute an attack.”
The Predator drone, flown out of Sicily and controlled via satellite from a base outside Las Vegas, struck the convoy with a number of Hellfire anti-tank missiles. Moments later French jets, most likely Rafales, swept in, targeting the vehicles with 500lb Paveway bombs or highly accurate £600,000 AASM munitions.