'Britain's official UFO investigation unit and hotline were closed down at the start of December. Since then reports of strange sights in the skies sent to the MoD have been kept for 30 days before being thrown out, the newly released policy document shows. The stance was adopted so defence officials would not have to publish the information in response to freedom of information (FoI) requests or pass it to the National Archives.

The memo, dated November 11, 2009, sets out the MoD's reasons for shutting its UFO unit and ceasing to invite the public to send in details of sightings. It notes that the number of reports the department received soared last year, taking up extra resources and diverting staff from ''more valuable'' defence-related activities.'

Read more: UFO Reports to Be Destroyed in Future by MoD