They led to three days of travel chaos and 1,000 flights being canceled or diverted, but drone sightings at Gatwick Airport last week are still managing to cause confusion and uncertainty.

Sightings of drones at the U.K.'s second-largest airport led to a shutdown with 140,000 passengers being affected and many having to cancel their Christmas holiday plans. Speculation on who the perpetrators were at the weekend resulted in confusion when two people were initially arrested but then released and exonerated on Sunday morning.

Police say they had 67 reports of drone sightings, calling them credible, and had also recovered a damaged drone near the perimeter fence of the airport. However, Jason Tingley, a detective chief superintendent at Sussex Police, told the BBC that wet weather could have washed away vital evidence and said there was "always a possibility that there may not have been any genuine drone activity in the first place."

Tingley also said no footage of a drone had been obtained and police were relying on witness accounts.

"We are interviewing those who have reported these sightings, are carrying out extensive house-to-house inquiries, and carrying out a forensic examination of a damaged drone found near the perimeter of the airport," Tingley told reporters, according to the BBC.