Thanks for your email. First of all, here's the MoD's response to a Freedom of Information Act request that mentioned this photograph:
http://www.mod.uk/NR/rdonlyres/8B65AF18 ... foreq3.pdf
The issue also arose in a Parliamentary Question tabled by Martin Redmond in the House of Commons in 1996, which can be seen at the bottom of the following link:
http://www.publications.parliament.uk/p ... 724w28.htm
Coincidentally, I've just written an article for UFO DATA magazine that mentions this photograph. As the July issue is on the point of coming out, I don't see any problem with copying you the relevant extract:
The Disappearing Photograph
When I took over responsibility for investigating UFOs at the MoD, one wall of my office was dominated by a spectacular image of a UFO. It was silver-coloured craft, perhaps no more a couple of hundred feet above the ground, if that. It looked diamond-shaped, but may have appeared triangular when viewed from underneath - this was something I'd come across in other investigations, and was a feature of some reports in the Belgian Wave and the Cosford Incident. A colleague told me the story surrounding the image. Apparently the UFO had been seen near Pitlochry in Scotland in 1990, and the photo had been sent to the MoD for analysis. I'm not able to go into the details of this analysis, but the conclusion was that this was a real object, perhaps 25 or 30 metres in diameter, as I recall. The image on my office wall was a blown-up copy of the original photo and served as a reminder of why UFO sightings needed to be investigated thoroughly. The photo came up occasionally in the course of my dealings with other specialists, one of whom had the same image on his office wall. "Take that, for example", he said to my sceptical boss on one occasion, pointing at the image. "It's not a fake. It's big. If we could just understand a bit more, we could maybe learn something about its aerodynamics, its propulsion system ...". His voice trailed off and the possibilities were left hanging in the air, like the UFO itself. One day, however, my Head of Division came in and removed the photo from the wall, locking it in his desk drawer. Despite the US denials, he had somehow convinced himself that Aurora did exist, and that this is what the photo showed. I alluded to the photo briefly in my first book, Open Skies Closed Minds, and this led to Martin Redmond asking a question about the photo in Parliament, and to various ufologists making FOI requests about it. The MoD's responses stated that the photo could not be located. This is a shame, because this might have been the best evidence we had in relation to the triangular-shaped UFOs. Did our best chance of ever resolving the mystery somehow slip through our fingers?
