There is speculation that the drone attack that shut down Gatwick Airport before Christmas was carried out by someone with extensive knowledge of the airport's operations.
The airport's chief operational officer, Chris Woodroofe, told British current affairs show Panorama that whoever was piloting the drone "seemed to be able to see what was happening on the runway".
British police responded to his comments as part of the programme, saying the theory was a "credible line" of enquiry.
Britain's second-largest airport was forced to close its runway in the run up to Christmas after drones started appearing on the site south of London in the most disruptive incursion from unmanned aerial vehicles at any major airport.
Almost four months on, no group has claimed responsibility and no charges have been laid for the disruption which affected at least 120,000 people across two days.
Woodroofe says all the evidence points towards the attack being carried out by an airport insider.
"It was clear that the drone operators had a link into what was going on at the airport," he said.
Woodroofe added that whoever was piloting the drone either had a clear view of the runway or was eavesdropping on the airport's radio or internet communications.
Further to this, the drone that was used in the attack was a model that the facility's drone detection system could not track.
British police told Panorama its investigation is ongoing and expected to take "some months to complete".