A Gatwick Airport official has said the drone disruption late last year was likely caused by someone with knowledge of operations at the airport.
A series of drone sightings over several days last December led to hundreds of flight cancellations.
Around 140,000 passengers were impacted as a result of the disruption, only days before Christmas.
The disruption included a full day of suspended operations on December 20th - a day that saw the drone reappearing every time authorities attempted to resume flights.
Chris Woodroofe, the Gatwick executive who oversaw the airport's response to the incident, says whoever was responsible knew what was happening at the airport.
Speaking to BBC Panorama, he said: "Every time [the] restart process began, the drone reappeared.
"It was clear that the drone operators had a link into what was going on at the airport - be that a visual link, be that a radio link, or even using the internet where much of this information is readily available".
He suggested whoever was behind the 'attack' could either see what was happening on the runway or was 'eavesdropping' on airport communications.
Police, meanwhile, told BBC that the possible involvement of an "insider" was a credible line of inquiry.
'Specifically selected' drone
Mr Woodroofe also indicated the drone was "specifically selected" as it could not be seen by a drone detection system which was being tested at the airport.
He dismissed suggestions that the number of sightings had been exaggerated - saying many of those who reported sightings were trusted staff at the airport.
"They knew they'd seen a drone. I know they saw a drone," he insisted.
In the months since the Gatwick incident, a small number of airports around the world have had to briefly suspend operations due to reported drone sightings.
That included a 30-minute suspension at Dublin Airport in February.
It is illegal to fly drones within five kilometres of Irish airports.