Two people who were held over the drone disruption at Gatwick Airport have been released without charge.
In a statement, Sussex Police said the man and woman arrested were no longer suspects following the widespread disruption of flights through the illegal use of drones.
Gatwick Airport Limited is now offering a £50,000 reward for information leading to the arrest and conviction of those responsible.
It is in addition to the £10,000 offered by Conservative peer Lord Ashcroft through Crimestoppers.
Sussex Police Detective Chief Superintendent Jason Tingley told Sky News officers had recovered a damaged drone on the north perimeter of the airport in Horley.
He said: “Obviously we will be doing everything we can with regards to forensically examining that drone and that is something that is being fast-tracked and expedited.”
It follows a police search at an address in Crawley on Saturday after the two people were arrested on suspicion of “disrupting services of civil aviation aerodrome to endanger or likely to endanger safety of operations or persons”.
In an earlier statement, the officer said: “Both people have fully co-operated with our inquiries and I am satisfied that they are no longer suspects in the drone incidents at Gatwick.
“It is important to remember that when people are arrested in an effort to make further inquiries it does not mean that they are guilty of an offence and Sussex Police would not seek to make their identity public.”
He told Sky News officers were acting on information passed on by the public when they made the arrests.
“I’m confident that that arrest was justified and of course over the last day or so we have been meticulously investigating their involvement and I am satisfied now that they are no longer suspects in this investigation,” he added.
The police chief said the two people released were being offered support by officers.
Speaking of the ongoing inquiry in his statement, Detective Chief Superintendent Tingley said: “Our inquiry continues at a pace to locate those responsible for the drone incursions, and we continue to actively follow lines of investigation.
“We ask for the public’s continued support by reporting anything suspicious, contacting us with any information in relation to the drone incidents at Gatwick.”
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”.
The disruption began at about 9pm on Wednesday and flight schedules have only just started returning to normal.
The closure of the airport disrupted about 1,000 flights and ruined the travel plans of more than 140,000 people.
Gatwick – Britain’s second busiest airport – serves more than 43 million passengers a year.
A spokesman for the airport said earlier: “Broadly, things are going in the right direction. By the end of the weekend, things should be back to normal.”
Gatwick said a full schedule had run on Sunday and that there were no cancellations related to drone activity, despite delays in line with “normal operations” during the busy winter period.
However, it said police and the RAF remained in place at the airport.
Meanwhile, Labour has accused the government of failing to act on the risks posed by drones at Gatwick and has called for an independent inquiry.
“The government was repeatedly warned about the risks posed by drones to aviation but failed to act,” said shadow transport secretary Andy McDonald.
“The delay in bringing forward legislation is indicative of this government’s failure to concentrate on the day-to-day business in front of them. They have taken their eye off the ball.”
According to The Times, Transport Secretary Chris Grayling put plans on hold as a result of pressure on his department, with civil servants diverted to deal with Brexit.
However, the Department for Transport (DfT) said the claims were “a combination of nonsense and gross misrepresentation”.
A DfT spokesman added: “The drones at Gatwick have been flown illegally. The government changed the law this year to make it illegal to fly drones within 1,000m of an airport or above 400ft. The law couldn’t be any more clear.”