A man and a woman arrested over the drone activity which caused mass disruption at Gatwick Airport have been released and are "no longer suspects", police have said.
The 47-year-old man and 54-year-old woman were arrested in Crawley on Friday evening
It comes as authorities discovered a damaged drone near to the perimeter of the airport.
Gatwick have now offered a £50,000 reward for information leading to the arrest and conviction of those responsible for the "illegal use of drones" which resulted in more than 1,000 flights being cancelled or diverted, affecting around 140,000 passengers.
Despite the couple being released, police have insisted they are "not back to square one".
Flights from the UK's second biggest airport were grounded for more than a day after devices were spotted inside the perimeter on Wednesday at around 9pm.
The airport fully reopened on Friday after tens of thousands of passengers had their travel plans disrupted.
Police searched a house in Crawley on Saturday as the pair were held on suspicion of "disrupting services of civil aviation aerodrome to endanger or likely to endanger safety of operations or persons".
But on Sunday, Sussex Police Detective Chief Superintendent Jason Tingley said: "Both people have fully co-operated with our enquiries 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 enquiries it does not mean that they are guilty of an offence and Sussex Police would not seek to make their identity public."
He later said: "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."
Labour has called for an independent inquiry after accusing the Government of failing to act on the risks posed by drones at Gatwick.
Shadow transport secretary Andy McDonald claimed there were missed opportunities to prevent the airport from coming under such an attack.
But a Department for Transport spokesman said the claims were "a combination of nonsense and gross misrepresentation".
He added: "The drones at Gatwick have been flown illegally. The Government changed the law this year to make it illegal to fly drones within 1,000 meters of an airport or above 400 feet. The law couldn't be any more clear."