London: Britain`s wartime prime minister Sir Winston Churchill, who led the country in the Second World War, also acted over "alien invasion", de-classified documents have revealed.
According to the documents, Churchill ordered senior aides to investigate unidentified flying object (UFO) sightings amid fears of an alien invasion and also demanded to know whether flying saucers spotted all over Britain could be from outer space, the `Daily Express` reported.
In a 1952 memo to Lord Cherwell, the Secretary of State for Air, Churchill asks: "What does all this stuff about flying saucers amount to? What can it mean?"
In the reply, the then prime minister was told that alleged UFO sightings could be explained by earthly phenomena such as optical illusions, mistaken identification of planes, birds and balloons and deliberate hoaxes.
He was briefed on a 1951 report by Sir Henry Tizard, a scientific adviser, blaming hoaxes, mistaken identity and natural phenomena.
Aides concluded: "Nothing has happened since 1951 to make the air staff change their opinion."