A PASSENGER jet came within 200ft of colliding with a fast-moving aircraft suspected to have been a drone in a mid-air near-miss Government officials have rated as among the most serious they investigate.

The UK Airprox Board said the captain of an Airbus A319 - a commercial passenger twin-engine jet airliner - spotted the aircraft heading almost directly overhead the aircraft in the opposite direction as he ascended to 18,000ft, six miles north of Barnard Castle, near Windy Bank.

The pilot of the Airbus plane, which is understood to have been flying from Leeds to Edinburgh, said the unknown aircraft passed close and in line with his right engine.

The incident on February 2 has been revealed in a report detailing inquiries into numerous drone mid-air near misses this year, including one involving a Boeing 737 passenger jet, at 9,500ft 12 miles south east of Newcastle Airport.

Air safety experts have expressed concerns over the soaring number of drone-plane near misses in UK air space.

Latest figures show there were 33 such incidents confirmed in the first five months of this year and 70 last year. There were 29 in 2015 and just ten in the five years before that.

Former RAF pilot Sion Owen Roberts, who trains people to fly drones, said they were potentially dangerous because their batteries are explosive.

He said: "Whilst I was serving in the RAF, it was always dangerous when we accidentally hit a bird. A bird can cause significant damage to an aircraft and the same sort of damage could occur from a drone strike. LiPo batteries are extremely volatile and you wouldn't want one disappearing down an aircraft engine."

A report on the incident in County Durham on February 2 states the pilot of the airliner initially believed it was a military fast jet, but later said he thought it could have been a drone.

It states: "The object/aircraft passed at high speed, very quickly, only being in view for approximately two seconds. It passed overhead, in line with engine 2 [right engine], estimated to be about 200ft above the aircraft. It was angular and appeared fast moving."

"The pilot took the radio and enquired with controller what had passed overhead. Controller responded to say there was only an aircraft about 20,000ft above their level."

The board concluded "safety had been much reduced below the norm to the extent that safety had not been assured".

In the Newcastle incident, the pilot spotted a dark drone "glinting in the sun" about 1,000ft from the Boeing 737.

The board stated the drone had been flown beyond "practical visual line of sight limits and was endangering other aircraft", but there had been no risk of collision.