An investigation has found there have been dozens of reported close calls between aircraft and mystery objects in the last two years – some of which occurred in London airspace.

The findings from Newsquest’s Data Investigations Unit found between 2017-19, there were nearly 20 reported incidents in London airspace.

One incident saw the Captain of a Boeing 757 business jet preparing for approach at Gatwick in busy airspace at nearly 4,800-ft when he reported “a fairly large, irregular shaped, dark black object pass down the left side at the same level, within 200-ft of the aircraft”.

Another saw two pilots spotting an object that appeared triangular in shape that was red and white in colour after departing London City Airport.

Both pilots assessed the object was not on a collision course but that it was dangerously close.

During a descent into Heathrow Airport an A320 pilot had spotted a “roundish” irregular shape with black, white, and orange stripes on the top.

He saw the unknown object passing on the left-hand-side of the aircraft, slightly below. It was only in sight for a short moment.

Since May 2017, the UK Airprox 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.

UFO experts have now said more should be done to uncover the truth about near misses in the skies following the findings.

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

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 suspension of flying at Gatwick Airport earlier this year leads the media and the public to assume such occurrences involve drones, but applying the UK Airprox Board's own guidelines, many of the reports being attributed to drone activity should more properly be characterized as 'unknown objects'.”

He continued: “In most cases, sightings turn out to be birds, weather balloons, plastic bags or bin liners, or Chinese lanterns, while some are indeed attributable to drones.

“However, other cases remain unexplained even after thorough investigation, and this is of concern, especially if we're missing a trick by being too quick to blame drones.”