Harrier jets in a dogfight with a "bright light" above the Queen's Highland home at Balmoral and a glowing white ball "like a flying jellyfish" over East Kilbride are among the alleged UFO sightings made to the Ministry of Defence.
• Colourised drawing of an object seen by witness 'Ian Macpherson' over Craigluscar Pictures: National Archives
The National Archives' latest batch of "alien activity", released yesterday, reveals sightings by the Scottish public, newspaper reports and official inquiries. The register shows that there were 61 reports between 2002 and 2006 alone.
The also include a "glowing white flashing light" seen over St Andrews on the evening of New Year's Day 2002, to the "huge white ball that glowing. Looked like a flying jellyfish" over East Kilbride.
While these may have been one-off reports, during April and May 2004 West Kilbride became Scotland's UFO centre, with ten reports that varied only slightly in their description of one or two bright yellow spheres travelling as "a tremendous speed". The records show no more sightings in the area until 2006, when a further two reports, again referring to "golden spheres" of varying numbers but described this time as "definitely solid guided crafts".
One of the most vivid descriptions contained within the newly-released files is of a sighting of a craft by an amateur photographer at Craigluscar Reservoir on the afternoon of 19 February 1994.
In his report to the MoD, the man, named in the press at the time as Ian Macpherson, said he had been facing away from the water when he became aware of a "humming noise, such as that from high voltage power lines. I also felt very uneasy and turned slowly towards the reservoir".
He was, he said confronted by a "disc-like object, which was definitely an aircraft" floating "fairly high in the air, and coming slowly in my direction". He described it as being the size of a jumbo jet, "metallic, and had several points of diffused light on its underside, inside a darker coloured 'rim'."
Despite being in possession of his camera, Mr Macpherson said he "felt unable to use it", only snapping the craft at the last moment as it moved noiselessly away with a "phenomenal" acceleration.
Nick Pope, a former MoD employee who has worked on the UFO files and who recorded Mr Macpherson's sightings, felt that the man was genuine in his description of the classic 'flying saucer'.
He said: "In a sense it was one of the things that persuaded me that the fellow was being straight with me, because I thought if he was going to do a hoax, he wouldn't do something so obviously cliched. But you could argue both ways.
"I had several conversations with him and we exchanged letters, he seemed straightforward and I think the point about him, as with many of the UFO witnesses, was that he had little or nothing to gain and quite a lot to lose in terms of ridicule by coming out with a story like this."
Other subjects raised in the files are media reports in 1996 of two Harrier jets engaging in a dogfight with a "bright light" over Balmoral - explained away as a "routine night goggle vision training" exercise.
The files are among 9,000 pages of UFO data released by the MoD, which also reveal that a lack of resources and "higher priorities" at the ministry prevented a full-scale study of the thousands of UFO reports that have been made since the Second World War.
The observation is contained in a 1995 internal memo from a wing commander in DI55, the branch of the Defence Intelligence Staff which was responsible for assessing UFO reports.The author concludes that there was no longer any reason to continue denying intelligence interest in UFOs, although the public perception of the unit as a "defender of the Earth from the alien menace" was "light years from the truth".
The memo led to an investigation and the findings concluded in 2000 that UFOs did not pose a threat, leading to the closure of the UFO desk in 2009.
Dr David Clarke, author of the book the UFO files and a lecturer in journalism at Sheffield Hallam University said: "Many people continue to believe the governments of the world know 'the truth' about UFOs and are concealing the fact that we are not alone in the universe.
"But I believe the truth is in these files. The files suggest that the UK government knows as much as we do about alien visitors and has no evidence to suggest we have ever been visited, despite the interest it has taken in sightings over the years. This is the truth, but will people believe it?"