UFO experts say more should be done to uncover the truth about near misses in the skies after an investigation has revealed reported close calls between aircraft and mystery objects.

There were three reported incidents in Sussex in one year alone – where passenger plane pilots confirmed sighting an unknown object from the cockpit.

Real life X-Files investigator Nick Pope has described the findings by Newsquest’s Data Investigations Unit as “fascinating and disturbing” and he said the reports made to the UK Airprox Board raise “important defence, national security and air safety issues”.

Newsquest is the owner of The Argus.

Since May 2017, the board, which aims to enhance aircraft safety, has reviewed 36 unknown object reports detailing airborne near misses across the country – and nearly a quarter were in the most serious risk category.

Author and journalist Mr Pope, who investigated UFO sightings for the Ministry of Defence in the 1990s, said: “It’s clear that pilots and air traffic services personnel are witnessing many near misses in UK airspace The Civil Aviation Authority said it was likely the vast majority of unknown near miss reports involved drones, model aircraft or balloons but the pilots could not be sure what they had seen.

The first incident in Sussex was reported in Uckfield at 7.20pm on July 14, 2017.

The pilot of an Airbus A319, a commercial passenger jet, reported flying at 7,000ft when he noticed an object close to the aircraft.

It was a black and shiny/metallic in colour and appeared to be a square/rectangular cube.

It appeared to be maintaining altitude and took a while (seven seconds) to pass by, making them believe it was hovering in a stationary position.

It was definitely not a weather balloon but because they could not make out any propellers on the side of the object – they were not sure whether it was a drone.

The report does not mention the airline involved but the A319 can carry up to 160 passengers and is operated by carriers including easyJet, American Airlines, United Airlines and Delta.

The next incident was recorded in East Grinstead at 3.35pm on August 12, 2017. The pilot of an Airbus A320 passenger jet reported he was passing 8,000ft when he saw a silver ball type object pass directly under the aircraft, very close.

He reported it to ATC and said the risk of collision was high.

The airline involved was not identified but A320 aircraft are among jets operated by easyJet and British Airways and can seat up to 180 people.

The final reported incident took place in Crawley at 2pm on May 5 this year. The pilot of an Airbus A320 reported that on departure from Gatwick, while in the climb, a “totally white object” resembling a shoebox sized cube with a round ball on top passed down the left-hand side, slightly above and within 50m of the aircraft.

The object appeared to be in level flight and there was no risk of collision.

The airline involved was not identified in the report but A320 aircraft are used by the likes of easyJet and British Airways.