A passenger jet carrying 200 people came within 90m of colliding with an unidentified flying object, an official probe has heard.

The Daily Mail website in Britain reports that despite an investigation, the UK Airprox Board – which examines reports of near misses – could not explain the ‘blue and yellow’ object which passed under the Airbus 320.

The incident happened on December 2 last year over Baillieston, east of Glasgow Airport, at around 3500ft, the Mail said. The airline involved has not been identified.

"The shocked pilot reported the collision risk as ‘high’," the Mail said.

"The A320 was descending into Glasgow in clear conditions with the sun behind, when both the plane’s pilots saw an object around 100 yards away."

The board’s report said: "The object passed directly beneath before either of the crew had time to take avoiding action or had “really registered it”, although they both agreed that it appeared blue and yellow (or silver) in colour and was “quite large” with a small frontal area.

‘The controller stated he was not talking to anyone else in that area and nothing was seen on radar.’

In its report, the board dismissed a variety of possible explanations, including that the object was an untraced aircraft, a manned balloon or a weather balloon.

It considered that the object might have been a glider but board members were not able to reach a conclusion.