A damaged drone has been found close to Gatwick Airport in the wake of severe disruption this week, its staff have confirmed to HuffPost UK.
It will undergo “fast-tracked” forensic tests in an attempt to find out who was controlling it.
This morning a couple arrested on suspicion of being behind the rogue drone were released without charge.
Sussex Police Detective Chief Superintendent Jason Tingley told the BBC: “Yesterday morning we discovered a damaged drone close to the perimeter of Gatwick Airport and that is of course a significant line of inquiry.
“We are not back to square one. Whilst these two people have been in custody, we have a number of lines of inquiry and persons of interest.
“We are still progressing those lines of inquiry, including house-to-house inquiries around the sightings of the drone.”
This comes as airport bosses offer a £50,000 reward through Crimestoppers for information leading to the arrest and conviction of those responsible for the criminal act that ruined the travel plans of thousands.
Flights in and out of the airport were suspended at about 9pm on Wednesday after two drones were sighted near the airfield, with hundreds of flights cancelled and more than 120,000 passengers affected.
Disruption continued throughout Thursday and airport bosses announced at about 9.30pm that the runway would remain closed, with activity from what was believed to be “a modified, professionally prepared drone” detected within the last hour.
Gatwick is Britain’s second busiest airport and serves more than 43 million passengers annually. The closure of the airport disrupted around 1,000 flights affecting more than 140,000 people.
Those with information are being urged to call Crimestoppers anonymously on 0800 555 111.
Police have reminded people willing to come forward that “payout on the reward will be made only if the information is given to Crimestoppers first”.