The Ministry of Defence closed its UFO desk in 2009 because it served "no defence purpose" and was taking staff away from "more valuable defence-related activities", newly released files have showed.
The latest tranche of declassified MoD UFO files showed the decision was taken to close the desk and its UFO "hotline" in a year when sightings reported to the department had trebled, but that, in more than 50 years, none had indicated the existence of "any military threat to the UK".
The 25 files, released by the National Archives, include 4,400 pages and cover the work carried out in the final two years of the MoD's UFO desk, from late 2007 until November 2009. They include accounts of alleged abductions and contact with aliens and UFO sightings near UK landmarks, as well as documentation of the decision to close the UFO desk.
The decision was taken to close the desk and bring to an end the "UFO hotline" by officials who deemed it had no "defence benefit", and the resources that were being devoted to it were taking staff away from "more valuable defence-related activities".
In a briefing for then defence minister Bob Ainsworth in November 2009, Carl Mantell, of the RAF's Air Command, suggested the MoD should try to significantly reduce the UFO task, "which is consuming increasing resource, but produces no valuable defence output". He told Mr Ainsworth that, in more than 50 years, "no UFO sighting reported to (MoD) has ever revealed anything to suggest an extra-terrestrial presence or military threat to the UK".
The memo said there was "no defence benefit" in the recording, collating, analysis or investigation of the sightings, adding: "The level of resources diverted to this task is increasing in response to a recent upsurge in reported sightings, diverting staff from more valuable defence-related activities."
Officials predicted a backlash from "ufologists" to the decision to close the UFO desk, and also noted that they had "deliberately avoided formal approaches to other governments on the issue", amid fears of "international collaboration and conspiracy". The files also revealed campaigns by ufologists for the government to investigate sightings more thoroughly, with letters sent to senior ministers, former prime minister Gordon Brown, and even the Queen, calling for more action.
After the closure, air traffic control centres and local police forces were advised to no longer refer UFO sightings to the MoD. An official MoD statement said: "The Ministry of Defence has no opinion on the existence or otherwise of extra-terrestrial life. However, in over 50 years, no UFO report has revealed any evidence of a potential threat to the United Kingdom. The MoD has no specific capability for identifying the nature of such sightings. There is no defence benefit in such investigation and it would be an inappropriate use of defence resources.
Furthermore, responding to reported UFO sightings diverts MoD resources from tasks that are relevant to defence. Accordingly, and in order to make best use of defence resources, we have decided that from December 1 2009 the dedicated UFO hotline answer-phone service and email address will be withdrawn. MoD will no longer respond to reported UFO sightings or investigate them."
Nick Pope, who previously worked on the MoD's UFO desk, said: "I hope people have as much fun reading these real-life X-Files as I had working on them. These documents don't resolve the UFO mystery but they certainly show how the phenomenon was just as intriguing to the government as it is to the public. These are the real-life X-Files. Most UFO sightings had conventional explanations, but a small percentage remained unexplained. These included cases where UFOs were seen by police officers, chased by pilots and tracked on radar. Whatever you think about UFOs, the release of these files shines a light on one of the most intriguing subjects ever studied by the British government".