Photographs of what is regarded to be one of the greatest hoaxes of the 20th century are expected to fetch up to £70,000 when they go under the hammer on Thursday.

Pictures of the Cottingley Fairies were taken in July and September 1917 by a 16-year-old girl called Elsie Wright – along with her nine-year-old cousin Frances Griffiths – in the village of Cottingley near Bingley in West Yorkshire.

A camera and a set of period photos, including some owned by the daughter of Frances, are going on sale at Dominic Winter Auctioneers in Gloucestershire.

In the summer of 1917, the two girls set out to prove the existence of fairies – unaware that their practical joke would go on to spark controversy and fool eminent figures such as Sir Arthur Conan Doyle.

Using Elsie’s father’s Midg quarter-plate camera, and with the use of coloured paper cut-outs and hat pins, they staged their scenes near the stream at the end of Elsie’s garden.

Elsie’s father, a keen amateur photographer, developed the prints – and in 1919, his wife Polly took prints of the two photographs to show members of the Theosophical Society in Bradford where they were giving a lecture on fairy life.

In 1920, Sherlock Holmes creator Conan Doyle became aware of the photographs and wanted to use them for an article on fairies he had been commissioned to write for The Strand magazine.

The girls later captured three more images of themselves with fairies during the summer of 1920.

The story has since been considered one of the most successful photographic hoaxes of the last century.

It was not until 1983 that Elsie and Frances admitted the photographs were faked, with Frances still insisting that the fifth photo, The Fairy Bower, was genuine.

Frances’ daughter, Christine Lynch, said her mother always maintained that the image was genuine but had taken it accidentally.

Ms Lynch said: My mother was glad the truth came out in the end.

She never thought she could take photographs of the fairies and she saw the grass had been shaped into a semi-circle nest.

Without thinking she took out the camera and set the timer, distance and exposure and it was only when it was developed, she saw there was actual fairies on it.

The 88-year-old, who lives in Belfast, said it was time to sell the images with the 100th anniversary coming up.

Ms Lynch added: I’m not sad to sell them and it’s time to do it and with 100 years coming up I thought it was a good time for them to go.

She said her mother Frances said the hoax ruined her life because she was looking over her shoulder the whole time – adding: As a little girl in 1920 she was not used to publicity and she didn’t like it at all, and it haunted her.

Auctioneer and photography specialist Chris Albury said: I think the contact prints of the fairies are incredibly significant photographs within the context of this remarkable story.

(c) Sky News 2019: Cottingley Fairies: Images of one of the 20th century’s ‘best hoaxes’ auctioned