Cottingley fairy photos
From Tardis Wiki, the free Doctor Who reference
Taken in 1917, the Cottingley fairy photos showed frolicking fairies. Discredited as a fake later, no less than Sir Arthur Conan Doyle believed in them. One of the photos showed Jasmine Pierce, a formerly Human Chosen One, now changed into a fairy herself. (TW: Small Worlds)
Behind the Scenes
Though, in reality, Sir Arthur Conan Doyle really did believe in the authenticity of the photos, his personal beliefs, at that time in his life, pre-disposed him to do so.
One of the fairies in the photo shown in extreme close-up in Small Worlds and on the Torchwood website had retouching done to it, so as to appear to have Jasmine's face.