The person or people who launched a drone attack at Gatwick in the week before Christmas had inside knowledge of the airport, a leading executive has said.

Chris Woodroofe, chief operating officer at Gatwick, told BBC’s Panorama: “It was clear that the drone operators had a link into what was going on at the airport.”

Aircraft cannot operate in an area where an “unmanned aerial vehicle” is flying. The drone attack closed the world’s most intensively used runway for 33 hours during the busiest week of the winter.

Between the evening of Wednesday 19 December and Friday 21 December, around 1,000 flights were cancelled at Gatwick.

The closure wrecked the travel plans of around 150,000 passengers and cost the airlines and airport at least £50m; easyJet alone lost £15m.

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In the BBC One programme, Mr Woodroofe said whoever was operating the drone seemed to be able to see what was happening on the runway.

“It was clear that the drone operators had a link into what was going on at the airport,” he said.

They had “specifically selected” a type of drone that was invisible to a drone-detection system that Gatwick was testing at the time.

In addition, they may have been watching activity on the airfield and listening in to radio traffic as the airport prepared on several occasions to re-open the runway. Each time, the drone reappeared.

Eventually, after military technology was deployed at the Sussex airport, the runway re-opened. But with 25 December only four days away, many of the disrupted passengers were unable to reach their Christmas destination.

Sussex Police is treating the possibility that an airport insider was involved as a “credible line of inquiry”.

A couple from Crawley were wrongly arrested for the drone attack. Paul Gait and Elaine Kirk were released without charge.

Mr Woodroofe, who led Gatwick’s response as “gold commander,” said: “There is absolutely nothing that I would do differently when I look back at the incident.

"Ultimately, my number one priority has to be to maintain the safety of our passengers, and that's what we did.”

Landing soon? Even after Gatwick's runway re-opened, operations were disrupted (Simon Calder)

Reports that there was actually no drone are rejected by Sussex Police in the programme. They recorded 130 separate credible drone sightings, almost all of which were by aviation or security professionals.

Mr Woodroofe described them as: “People I have worked with for a decade, people who have worked for 30 years on the airfield, who fully understand the implications of reporting a drone sighting.

“They knew they'd seen a drone. I know they saw a drone. We appropriately closed the airport.”