IT took some paper fairies and a handful of hatpins to create a childish prank that became one of the world’s most famous photographic hoaxes.

The Cottingley Fairies fooled scientists, academics, photography experts, even Sir Arthur Conan Doyle himself. The remarkable case sparked a debate that continued through the 20th century, until the two cousins at the centre of it finally admitted their photographs were faked. By that time Frances Griffiths and Elsie Wright were elderly women, and had long since fallen out over a prank that started in the summer of 1917 and quickly got out of hand.

They had no idea that Conan Doyle, creator of Sherlock Holmes, would become so fascinated by their fairy images that he would give them two expensive cameras to take more. Next year is the 100th anniversary of their final series of Cottingley Fairies photographs, taken in 1920 with a second camera gifted by Conan Doyle. Now that camera - a folding quarter-plate Cameo, manufactured by W Butcher & Sons, has ‘come home’, having been acquired by the National Science and Media Museum.

The museum already has the other Cameo gifted by Conan Doyle, and the original Midg camera used to take the first two fairy photographs. The latest camera acquired by the museum was put up for auction this year by Frances Griffiths’ daughter, Christine Lynch, bought by the museum for £3,400. It completes the museum’s collection of cameras relating to the famous fairy story - one of the most famous examples of image manipulation.

Looking at the photographs through a 21st century lens, it’s difficult to see how they fooled so many. But they were taken between 1917-1920 - which was, as National Science and Media Museum head curator Geoff Belknapp says, “a different world”.

“This isn’t a case of double exposure or messing around with negatives - they were very carefully framed images, which is why they were so believable for so long. People couldn’t see the mechanics of deception,” adds Geoff. “The mystery of the image-making, and how these young women managed to trick everyone, is partly why this story has fascinated us for so long.

“Conan Doyle’s involvement has added to the interest over the years. You have these two young women, Doyle’s article in The Strand bringing their images to public attention, experts trying to prove it was all a forgery, Frances and Elsie eventually admitting they were fakes - then Frances insisting that one was real.

“The Cottingley Fairies story is one of the most enduring in photographic history. To this day, it’s shrouded in mystery and speculation - objects relating to it remain some of the most enquired about in our collection, and continue to capture the public imagination as they did 100 years ago.”

Frances was nine and Elsie 16 when they wandered down to Cottingley Beck one July afternoon in 1917. Like many girls of the time, they had a copy of Princess Mary’s Gift Book and, inspired by its fairy illustrations, decided to make their own versions. Pinning their cut-out drawings to trees and leaves, the girls used a camera belonging to Elsie’s father to take photographs of the dancing ‘Beck Fairies’ and, later, a gnome.

While Elsie’s father, an amateur photographer, never doubted the images were fakes, his wife was more inclined to believe and, in 1919, she took them to a meeting of the Theosophical Society in Bradford. They went on display and photography experts claimed they were real. And so began a century of debate on the existence of fairies.

When Conan Doyle, a leading voice of the spiritualist movement, wrote about the photographs for The Strand Magazine, Frances and Elsie found themselves becoming famous.

“That period, after the First World War, was a time of great sadness and recovery,” says Geoff. “The story of these images is a big part of that. Conan Doyle’s son was killed in the war; like many people in that time of huge loss, he became interested in spiritualism.”

Convinced the Cottingley images were real, Conan Doyle wrote about them in his 1922 book The Coming of the Fairies; supporting the existence of fairies on ‘eye-witness’ accounts of Elsie and Frances. But doubt was already growing when, in 1920, he handed the girls a second quarter-plate Cameo. On the basis of the cousins’ correspondence in later life, Geoff says it seems they went ahead with taking more fake photographs simply to please him. “He believed in them and they didn’t want to shame him, publicly,” says Geoff.

There may have been mischief at work too. Frances’ memoirs reveal an amusing account of a trip to Cottingley Beck with Geoffrey Hodson, a psychic sent by Conan Doyle. The girls pretended to see fairies, making fun of Hodson who claimed he could see them too. Frances dismissed him as a “phoney”.

Conan Doyle initially changed the girls’ names to Iris and Alice, to protect their anonymity, when he published their photographs, but gradually they became known, and the attention was intense. Frances was uncomfortable with it and had no time for “theosophists, mediums, spiritualists and the rest”, her daughter told the T&A when the memoirs were published in 2009.

But while Frances eventually admitted the images were fakes, there was one that she insisted, to her death in 1986, was genuine. And it is this second Conan Doyle camera, now in the museum’s collection, that it is thought to have taken that final fairy image. Taken at Cottingley Beck, it is of a ‘nest of fairies’, which Conan Doyle called The Fairy Bower.

“The fairies in this last photograph are more translucent and ethereal, there’s a marked contrast to the earlier ones,” says Geoff. “The second Cameo from Conan Doyle is smaller than the first camera he gave them and we know for certain it was used to take three photographs in 1920. Although the second camera was given to them in December, the labels we have say the last pictures were taken in August, but there’s enough potential for the dates to be fudged. The provenance comes from the family.”

Adds Geoff: “The story for us is the cameras, and the photographs that were made from it. Our Cottingley Fairies items are displayed in the Kodak Gallery and next year we hope to develop new galleries. Cottingley is so close to the museum; this is a story heard around the world but here there is a sense of ownership of it. “

The museum collection also includes original prints of the 1917-1920 photographs and letters by Elsie and Frances in the 1980s, when they were elderly women. Among the correspondence is a 1983 letter from Elsie to Geoffrey Crawley following articles he wrote in the British Journal of Photography about ‘That astonishing affair of the Cottingley Fairies’. Elsie’s letter expresses her desire to reveal the truth about how the photos were taken - more than 60 years on.

Also in the collection are watercolour drawings by the girls, including one of a fairy that Elsie drew in later life during discussions with Crawley.

Who knew what really happened that day Frances absent-mindedly clicked the little Cameo camera, taking a photo she insisted was genuine. A hundred years on, those dancing fairies continue to charm us.