During a conference call between ministers, chaired by Transport Secretary Chris Grayling, it was agreed the 67 drone sightings were legitimate.

The airport has spent £5m since Wednesday on new equipment and technology to prevent copycat attacks.

About 1,000 flights were affected during the airport's 36 hours of chaos.

Sussex Police has insisted it was not "back to square one" after releasing an arrested man, 47, and woman, 54, without charge on Sunday.

The hour-long call included David Liddington for the Cabinet Office, the Home Secretary Sajid Javid, Security Minister Ben Wallace, Aviation Minister Baroness Sugg, a defence minister, the airport and police.

A government source said the force accepted that there had been "poor communications".

Det Ch Supt Jason Tingley said at the weekend it was a "possibility" there had never been a drone, as police had not been able to acquire any footage.

Asked about this, he said: "We are working with human beings saying they have seen something."

He later clarified the force was "actively investigating" 67 reports of sightings and there were some "persons of interest" but would not reveal if officers were close to making any further arrests.

 Flights resumed from Gatwick Airport on Friday

About 140,000 passengers were affected

During the conference call, it is understood the Cabinet Office "pushed" the Ministry of Defence and the Home Office to update their rapid deployment protocol.

They also discussed defence systems across the UK's airports, after discussions were had with all airport CEOs on Friday.

 The airport was forced to shut its runway for spells on Wednesday and Friday and for all of Thursday

The airport has offered a £50,000 reward, through Crimestoppers, and another £10,000 has been put up by the charity's chairman Lord Ashcroft to catch the culprits responsible for the drama, which affected some 140,000 passengers.

A damaged drone found near the perimeter of the airport near Horley, close to the last reported sighting, is also being examined.

A spokesman 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 the airport's operations."

Authorities regained control over the airfield early on Friday after the Army deployed unidentified military technology.

It is believed that the Israeli-developed Drone Dome system, which can jam communications between the drone and its operator, was used.

However, experts have said it does not enable the person responsible to be tracked down and captured.

John Murray, professor of robotics and autonomous systems at the University of Hull, said it could only "take the drone out of the sky".