Prompted by a series of Freedom of Information Act requests for UFO related documents, the British Ministry of Defense decided to transfer some of its UFO files to National Archives at Kew, making them available to general public.

First set of documents was transferred in May 2008. Another batch was released in October 2008, followed by the third one in March 2009.

Over the next three years, the MoD plans to release 160 files in total. The files can be download free of charge for the first month following the release.

The documents contain details of 8,000 UFO sightings by members of general public, as well as police officers and military personnel, covering the period from 1981 to present.

The latest instalment of files was transfered from the MoD in August 2009.

In 1957, US Air Force lieutenant Milton Torres, based at RAF Manston in Kent, was ordered to scramble in his F-86 Sabre fighter, and attack a UFO hovering above Norfolk, England.

He was told to fire all 24 of his missiles at the UFO, which he describes as being "as big as an aircraft carrier."

When Torres was just in range of the target, ready to fire, the UFO disappeared off his radar screen at estimated 10,000 mph.

Torres said he was visited afterwards by a security official who warned him not to talk about the incident.

His encounter is one of many cases described in 19 UFO related files released by MoD in October 2008. The Sun: Top Gun vs Alien (October 20, 2008)