A man and woman arrested in connection with drone sightings that grounded flights at Gatwick Airport have been released without charge.
An aircraft prepares to land at London Gatwick Airport after flights resumed following the closing of the airfield due to sightings of drones. Photo: AFP
The 47-year-old man and 54-year-old woman, from Crawley, West Sussex, were arrested on Friday night on suspicion of "the criminal use of drones".
Sussex Police said the pair were no longer suspects.
A damaged drone found close to the airport on Saturday was being forensically examined, the force added.
Detective Chief Superintendent Jason Tingley said it was "a working assumption" the device could be connected to their investigation, but officers were keeping "an open mind".
"We are also going through many reports of sightings of drone activity over the last few days," he said.
"We are meticulously going through that information to see if that produces any other further lines of inquiry, and also where we may focus our efforts in terms of house-to-house inquiries, CCTV footage, and any other information that will help us work through this investigation."
He said there was no available footage of the drones and police were relying on witness accounts.
He added there was "always a possibility that there may not have been any genuine drone activity in the first place", but they were working on a range of information from members of the public, police officers and staff working at Gatwick who had reported otherwise.
Flights were suspended for more than 36 hours when a device was first spotted close to the runway on Wednesday night.
Mr Tingley said the arrested man and woman had "fully co-operated" with inquiries after information was received from a member of the public.
Talking about the disclosure of their personal details in the press, he said he was satisfied their arrest was lawful, and stressed that officers would never reveal such information.
"We would not have chosen in any event to provide that information to anyone... and one might say that's probably hindered us in terms of how quickly we've been able to get to a resolution in terms of them being released from custody," he said.
Gatwick Airport Limited has now offered a £50,000 ($NZ94,000) reward through Crimestoppers for information leading to the arrest and conviction of those responsible for disrupting flights.
About 1000 aircraft were either cancelled or diverted, affecting about 140,000 passengers, during three days of disruption.
On Sunday the airport said it was operating as normal but there had been "some knock on effect". Passengers have been urged to check with their airline for the latest information.
Authorities finally regained control over the airfield early on Friday after the Army deployed unidentified military technology.
It is believed that the Israeli-developed Drone Dome system, which can jam communications between the drone and its operator, was used.
However, experts have said it does not enable the person responsible to be tracked down and captured.
John Murray, professor of robotics and autonomous systems at the University of Hull, said it could only "take the drone out of the sky".
- BBC