After more than 50 years faithfully recording reports of UFOs and flying saucers, and patiently answering questions from the public, the MoD eventually decided it was a waste of money, newly released documents show.

One file released by the National Archives includes a letter to the then prime minister in 2008. “Dear Gordon Brown,” it says, “Do you believe the British people have the right to know if our world has been contacted by alien civilisations?” The letter, like hundreds of others, was passed on to RAF Air Command in High Wycombe. A correspondent in Australia (the names of individuals have been redacted from the files) wrote to the Queen complaining that the British government “continues to refuse to reveal the truth behind their files and reports of unidentified flying objects”.

The writer had tried to contact various UK government bodies – the MoD, the RAF, even MI5 – to persuade them of the “seriousness of this UFO security issue”. A schoolchild from Altrincham, Cheshire, asked whether there was life “outside our planet … I have the right to know”. An RAF official replied: “It’s an interesting question which we remain totally open-minded about.” The official added: “I am enclosing some RAF ‘goodies’ that I thought you might like.”