The desk was closed by the Ministry of Defence in December 2009 despite a surge in reported sightings and the disclosure came in files released by the national archives in London, relating to reports of UFOs or unidentified flying objects between 2007 and November 2009.
The national archives has been releasing declassified MoD files on UFOs for the past five years and this is the 10th and final tranche. They show UFOs were reported over several United Kingdom landmarks, including the Parliament building and Stonehenge.
"Despite what many people think, and claim, the MoD does not have any expertise or role in respect of UFO/flying saucer matters or the question of the existence or otherwise of extraterrestrial life forms, about which it remains totally open-minded," UK defence officials repeatedly told members of the public.
Reports were examined and logged, they explained, "solely to establish whether what was seen might have some defence significance".
In the most recent case, dating back to February 2008, a member of the public reported seeing the craft hovering over the Palace of Westminster in central London for about half an hour.
The object was said to have green, red and white lights and remained static in the clear, cloudless sky.
An official at the UFO desk wrote to the member of the public stating that the department was "satisfied that there is no corroborating evidence to suggest that the UK's airspace was breached by unauthorised aircraft".
Soon after the decision to shut down the desk was taken and an official MoD statement from the time said the department had "no opinion on the existence or otherwise of extra-terrestrial life".
"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we have decided that from December 1, 2009 the dedicated UFO hotline answer-phone service and email address will be withdrawn. [The] MoD will no longer respond to reported UFO sightings or investigate them," it added.
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