New details about the incidents involving drones that caused travel delays at Gatwick Airport in the lead up to Christmas suggest they could have been an insider job.
Drones were spotted flying around the London airport days out from Christmas last year, causing chaos with flights in and out suspended for more than 30 hours, disrupting tens-of-thousands of travellers' plans.
But while nobody has been charged with the crime, new details have come forward suggesting the offender or offenders knew how airports ran.
BBC reports a security officer made the sightings - spotting two drones at one end of the air field. The drones disappeared, but three hours later, but when workers went to inspect the runway a drone had returned, a pattern repeated throughout the next day.
Gatwick Airport's Chris Woodroofe told the BBC whoever it was operating the drones had insider knowledge about how airport procedures worked.
"They clearly had some idea about how airports work and had some intelligence as to what we were doing," he said.
However, since the military set up counter-drone equipment at the airport, the number or sighting has dropped significantly.
Since the incidents at Gatwick, airports around the world have been investing in technology to counter drone usage.