Ministry of Defence staff recorded sightings of alien craft over Wallasey Town Hall and a saucer-shaped unidentified flying object over Waterloo Bridge, it was revealed today.

See also: Map: County hotspot for UFO sightings

Files detailing hundreds of sightings of unexplained objects in the skies above Britain have been opened to the public for the first time.

Shropshire has had its fair share of UFO sightings, with more than 20 reported over the last 40 years, according to research by Virgin Media released in March.

They include a sighting on the A5 towards Telford, where a motorist saw 13 coloured lights in the sky which appeared to be circling an object about 100ft in size.

The information was considered sufficiently important for a form to be produced which is kept by police stations and airbases ready to record details of such reports.

Briefing documents for government ministers facing questions about policy on unidentified flying objects also form part of the release of documents at the National Archives in Kew.

But the Ministry of Defence was not investigating the possibility of visitors from outer space.

Defence intelligence staff were more interested in checking UFOs were not signs of earthly covert spying missions by other countries.

Nick Pope, who worked for the MoD for 21 years and was responsible for investigating the sightings, said: “While there’s no evidence of little green men in these files, they should be of immense interest to sceptics and believers.

“Most of the UFO sightings here are probably misidentifications of aircraft lights and meteors, but some are more difficult to explain and include UFOs seen by police officers and pilots and cases where UFOs have been tracked on radar.”

Eight files have been released after a Freedom of Information request by UFO researchers.

Over the next four years more than 150 files will be thrown open.