Detectives hunting the Gatwick Airport drone operator have found a damaged device on the airfield, police have confirmed.
It comes as the prime suspects in the probe - a man and a woman from nearby Crawley - were released without charge by Sussex Police, 36 hours after being held on suspicion of "disrupting services of civil aviation aerodrome to endanger or likely to endanger safety of operations or persons".
The pair, aged 47 and 54 respectively, made no comment as they darted inside their home.
Police will now turn their attentions to the damaged drone found within the airport perimeter.
Detective Chief Superintendent Jason Tingley said: "Yesterday morning we discovered a damaged drone close to the perimeter of Gatwick Airport and that is of course a significant line of enquiry.
"We are not back to square one. Whilst these two people have been in custody, we have a number of lines of enquiry and persons of interest," he said.
"We are still progressing those lines of enquiry, including house-to-house enquiries around the sightings of the drone."
He said the force had received more than 67 calls from members of the public, airport staff and police officers stationed at the airport and detectives were working to determine whether they were confirmed.
Supt Tingley assured members of the public that the specialist measures, including those provided by the military, would remain in place until it was deemed appropriate for efforts to be scaled back.
"I'm confident we will get more information we will respond to, then we will progress an enquiry in order to identify the perpetrator," he said.
Around 1,000 flights were cancelled or diverted after drones were spotted inside the perimeter of the UK's second biggest airport on Wednesday and approximately 140,000 passengers were affected.
It comes as the airport offered a reward of £50,000 for information leading to the arrest and conviction of those responsible for the chaos.
Police searched the house in Crawley on Saturday as the pair were arrested.
Supt 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.
"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."