In a phone interview on Sunday night, Chief Tingley said that the couple had been held for “approximately 35 hours” for questioning because the police “needed to be really sure what we were dealing with.”

He defended the arrests as “lawful” but criticized the public disclosure of “personal details” about the couple and information about the investigation. The couple’s age, identities and images were first published by The Telegraph. A member of Parliament, Henry Smith, whose constituency includes Gatwick Airport, identified the couple to The New York Times.

The Sussex police have declined to officially name the couple, and the chief said the police had offered them “full support” after they were released — including the presence of two officers outside their home if they needed it.

Chief Tingley said the damaged drone was found on Saturday morning near the perimeter fencing of Gatwick, in the small town of Horley, by a member of the public who alerted the police. He said an examination by a forensic science team in Britain was being “prioritized and fast-tracked.”

Investigators are looking for two things, he said: digital data on the drone and human DNA. He added, “We expect results within the next 12 hours.”

Earlier, he told the BBC that the authorities had an “open mind” about whether the device found could be one of the drones that had buzzed Gatwick Airport, Britain’s second-busiest. He said the authorities were sifting “many reports of drone activities” over the past few days, poring over CCTV footage and making house-to-house searches.

Asked by the BBC about the possibility that there had been no drone incursions at Gatwick in the first place, he said it was “always a possibility,” but added that the authorities had to go on the reports of the number of people who said they had seen drones “or something that looked like a drone” in the sky near the airport.