BLOW-UP dolls are known for being popular at stag and hen dos across the UK.

       But if you're wondering who invented them and if they were used during World War II then keep on reading - we explain.

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       Blow-up dolls are popular at sports events and festivals Who invented blow up dolls?

       Blow-up dolls are popular at sports events and festivals.

       But despite their popularity, it's unknown who invented them.

       The earliest sex doll was created by Dutch sailors in the 17th century.

       They used a doll fashioned cloth to relieve sexual tension during long stretches at sea.

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       The first recorded manufactured sex-doll appeared in "The Sexual Life of Our Time" written by psychiatrist Iwan Bloch and published in 1908.

       After the sexual revolution during the 1960s, adverts began appearing in magazines featuring dolls with different hair colours and styles.

       Did Adolf Hitler create sex dolls?

       During World War 2, it was believed that Nazi leader Adolf Hitler ordered sex dolls to be given to German troops fighting on the front line.

       It was rumoured that a scheme called the Borghild Project aim to combat the spread of syphilis among Nazi troops by supplying them with sex dolls.

       It was supposedly inspired by Heinrich Himmler's 1940 memo to Hitler that there was a syphilis problem in Paris brothels.

       He wrote in his report: "The greatest danger in Paris is the widespread and uncontrolled presence of whores."

       It's reported Hitler approved the project to provide the dolls, which were transported in soldiers backpacks.

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       It's claimed Hitler approved the project and designers began working on the doll or "gynoid" whilst being supervised by Franz Tschackert at the German Hygiene Museum.

       However, a lack of evidence supported this theory led to it being deemed as a hoax in the early 2000s.

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       The main evidence supporting this were two photographs reportedly rescued from the trash which was later proven to be a hoax.

       No employees at the German Hygiene Museum weren't able to recall that the project existed when asked.