Suggestions that there may never have been a drone at Gatwick airport were down to “poor communications” rather than a genuine possibility that the incident was baseless, police have told the government.

Ministers were briefed on the latest situation at the airport in an hour-long conference call chaired by the transport secretary, Chris Grayling, on Monday.

On Sunday, Sussex police said it was conceivable that there might never have been a drone, despite the massive disruption in the run-up to Christmas.

One officer said that there was “always a possibility that there may not have been any genuine drone activity in the first place”.

They also said wet weather could have washed away evidence and that there were no photographs or video of the drone in Gatwick airspace.

However, following the call, a government source said police accepted there had been a communications failure.

And later on Monday Sussex police moved to quash speculation about the drone reports, saying it could “unequivocally state” there had been “numerous illegal drone sightings at the airport over three days from 19 to 21 December”.

The Sussex force’s deputy chief constable, Jo Shiner, said: “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.”

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 the Cabinet Office minister, David Lidington – Theresa May’s de facto deputy; the home secretary, Sajid Javid; the security minister, Ben Wallace; and the defence minister Stuart Andrew.

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.

Grayling briefed on a meeting he held on Friday with airport chief executives to prevent copycat attacks, while police were said to be working with the Home Office to “amplify” the message that flying drones near airports is illegal.

About 1,000 flights affecting 140,000 passengers were cancelled or diverted across three days after drones were spotted inside the perimeter of the UK’s second biggest airport on Wednesday.

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.

Det Chief Supt Jason Tingley of Sussex police said the force 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.”