UK police have admitted that some of the drones spotted near Gatwick Airport during major pre-Christmas disruption may have belonged to police.

Investigators have searched 26 potential launch sites near the airport, but have not located the device that disrupted about 1,000 flights on the 19th and 20th December.

The incident ruined the travel plans of more than 140,000 people

Speaking to the BBC, Sussex Police Chief Constable Giles York apologised to two people who were held in custody for 36 hours on suspicion of involvement in the disruption.

He said he was "really sorry" for the pair who said they felt "violated" after being questioned in custody for 36 hours before being freed.

He said they are no longer suspects in the investigation – although he insisted the grounds on which police arrested the pair was “well-founded” in lawful suspicion.

Speaking to the BBC, he said the detention was necessary in order to dispel any uncertainty “in the first instance” and insisted that it would have been worse to release them while they were still under investigation.

"We are able to exhaust all our lines of inquiry on that first instance and, however hard it is, able to release him from police custody saying he is no longer a suspect in this line of inquiry,” he said.

"That's why we took the time - in order to allow him the best opportunity to put his life back on the rails."

Disruption

Police have now ruled two drones discovered near the airport out of their investigations.

"I don't think we have found the drone responsible for this at this time,” said chief Constable Giles.

"I think the fact that we have found two drones so far as a result of this does show the extent of the search that has been carried out.

"I am led to believe that we are able to rule those drones out of this investigation at this time."

Passengers queue for flights at Gatwick Airport as the airport and airlines work to clear the backlog of flights delayed by the drone incident earlier this week, 22-12-2018. Image:  Gareth Fuller/PA Wire/PA Images

Drone

Police previously said it was "possible" there was no drone at all - though they later backtracked.

Chief Constable York said he was "absolutely certain that there was a drone flying throughout the period that the airport was closed."

Police received 115 reports of sightings in the area, including 92 which have been confirmed as coming from "credible people," he said.

However he admitted that some of the sightings may been of the police’s own machines that were searching for the offending device.

"Of course, we will have launched our own Sussex Police drones at the time with a view to investigate, with a view to engage, with a view to survey the area looking for the drone, so there could be some level of confusion there," he said.

Security

He added that new military technology was now in place in Gatwick to tackle rogue drones.

Gatwick Airport is offering a £50,000 reward for information leading to the arrest and conviction of those responsible for the disruption.