Suggestions that there may never have been any drones at Gatwick were down to “poor communications”, police have said.
Ministers were briefed on the latest situation at the airport in a conference call amid growing criticism of the handling of investigation by Sussex Police.
On Sunday, a man and woman arrested in connection with the inquiry were released without charge following two nights in custody after officers said they were no longer suspects.
A senior detective then said it was a “possibility” that there may never have been any drones in the area, despite scores of sightings which led to the closure of the airport for three days and caused massive disruption for passengers.
Sussex Police Deputy Chief Constable Jo Shiner said on Monday afternoon: “We can unequivocally state that there have been numerous illegal drone sightings at the airport over three days from 19 to 21 December.
“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.
“The impact of this criminal and reckless behaviour has been enormous and we are determined to locate those responsible to bring them to justice.
“We are investigating this under the Aviation and Maritime Security Act which carries a maximum sentence of life imprisonment.
“We urge the public to contact us if they feel they have information that will help us in our investigation.
“Contacting Crimestoppers they can do this anonymously. We ask the public to continue to support us by reporting any suspicious activity.”
There had been more than 200 sightings since the first drone was spotted in the Gatwick area on Wednesday, with police taking 67 statements, including from police officers and airport staff.
Police are also carrying out a forensic investigation of a damaged drone found near the airport perimeter, close to the last reported sighting.
In a statement, the airport said: “We are clear that there were multiple confirmed sightings of drone activity at the airport. Therefore we took the necessary actions to ensure the safety of passengers using our airport.
“Safety will always be our number one priority. We continue to support the police with their investigations into this illegal and deliberate act to disrupt Gatwick Airport’s operations.”
The conference call was joined by Cabinet Office Minister David Lidington – Prime Minister Theresa May’s de facto deputy – Home Secretary Sajid Javid, Security Minister Ben Wallace and Defence Minister Stuart Andrew.
Mr Lidington was said to have pressed for the Home Office and the Ministry of Defence to update their rapid deployment protocols for signing off requests for military assistance.
Mr Grayling briefed on a meeting he held on Friday with airport chief executives to prevent copycat attacks, while police were said to be working to with the Home Office to “amplify” the message that flying drones near airports is illegal.
Sussex Police meanwhile have denied that the hunt for the perpetrators was “back to square one” following the release of the 47-year-old man and the 54-year-old woman, from Crawley, close to the airport.
The pair were originally arrested and their home searched following a tip-off from a member of the public.
Detective Chief Superintendent Jason Tingley said on Sunday that there were some “persons of interest” but would not reveal if police were close to making any further arrests.
“We are interviewing those who have reported these sightings, are carrying out extensive house-to-house inquiries and carrying out a forensic examination of a damaged drone found near the perimeter of the airport near Horley, which is close to the last reported sighting,” he said.
Gatwick has offered a £50,000 reward, through Crimestoppers, and another £10,000 has been put up by the charity’s chairman, Lord Ashcroft, for the arrest of those responsible for the chaos
Mr Tingley warned police could not rule out the risk the culprits would strike again at Gatwick or another airport.
“Someone, somewhere knows either the perpetrator or perpetrators responsible for this, or has information relating to these incidents,” he said.
“Our tactical response, should there be any more drone sightings, is still in place.”