Police field tip-offs in Gatwick drone probe after 50,000 pound appeal

British police probing the Gatwick Airport drone mystery that grounded Christmas getaway flights last week have received around 30 pieces of "useful information" in the last 24 hours, a police-backed charity said on Monday.

The tip-offs came after the airport on Sunday began offering a 50,000 pounds (USD 63,000, 56,000 euro) reward for information on dozens of drone sightings which led to the three days of disruption.

"Within the first 24 hours we had close to 30 pieces of useful information that we passed onto police," a spokesman for CrimeStoppers, a charity that aims to aid police in solving crimes, told AFP.

"It's been a good response," he said, adding it pays out rewards if details provided -- even anonymously -- lead to the arrest and conviction of perpetrators.

Gatwick, Britain's second-busiest airport, was forced to close its only runway repeatedly between last Wednesday and Friday due to the drone reports, impacting nearly 140,000 passengers.

It launched the new appeal for information Sunday after police released without charge a local couple arrested Friday over the incident.

Paul Gait and Elaine Kirk, who live in nearby Crawley, said in a statement Monday they felt "completely violated" by their two-day detention.

The police also on Monday defended themselves against criticism of their handling of the entire incident.

It followed a detective admitting it was a "possibility" no drones had actually been in the area -- despite the discovery of a damaged device near the airport perimeter now being forensically examined.

"We can unequivocally state that there have been numerous illegal drone sightings at the airport over three days from 19 to 21 December," said Sussex Police deputy chief constable Jo Shiner.

"There were numerous reports clustered around 37 occasions where a drone or drones were seen and I am keen for those responsible to be brought to justice."