True story behind The Human Centipede - its link to Nazi Germany as director talks new filmThe plot of the controversial film is steeped in horrifying history, here's what inspired the graphic moviesThe iconic Dutch horror film The Human Centipede by director Tom Six was released in 2009 and produced some rather visible reactions. It was condemned for its revolting and grotesque scenes, which showed a German surgeon who kidnaps three tourists, tortures them, before he joins them surgically, mouth to anus, forming a "human centipede" - a conjoined triplet. The controversy would continue with Six's sequel to the film The Human Centipede 2 Full Sequence, which was only released in the UK in 2011 after substantial cuts and edits, after the British Board of Film Classification BBFC refused to give the film an 18 certificate unless the film cut a large number of graphic scenes - including masturbation with sandpaper, rape with barbed wire, and the brutal murder of a newborn baby. The final film in the torture trilogy The Human Centipede 3 Final Sequence was critically panned and derided for its enjoying of sexual violence and self-serious focus on punishment in the criminal justice system. Tom Six's next film is psychological thriller The Onania Club, which is due out later this year, so we think this would be the perfect time to look at what inspired the Dutch director's disturbing iconic trilogy. Tom Six, director of The Human Centipede series. Image Daily Record The Human Centipede There were some key inspirations for Six's original horror flick, but some are much more serious than others. The main inspiration for the film came from a joke that Six had told to his friend where he explained a punishment for child molesters which would see their mouths stitched to the anus of a fat truck driver. As the film germinated in Six's mind, he took inspiration from real life and abhorrent episodes in recent history. Six's chief historical inspiration was the Nazi experiments conducted on Concentration Camp prisoners in World War Two, including the diabolical experiments of Dr. Josef Mengele. German Nazi doctor and war criminal Josef Mengele Image Getty The experiments saw prisoners across Europe forced to participate in tests that mostly ended in death, trauma, disfigurement, and permanent disability. The vile examples of medical torture included tests on twins, with twins being forcibly sewn together to become conjoined, and dying eyes in twins to see how they would react. If one twin died in the experiment, the other would always be killed. Read more Horrifying true crimes The monsters also conducted bone, muscle, and nerve transplants on prisoners without the use of anesthesia. There were also tests of new drugs, weapons such as mustard gas and poisons and sterilization on prisoners, against their will, which would have long-lasting medical reprecussions. Auschwitz Concentration Camp in Poland, where numerous atrocities were committed. Image BBC The film also features victims of multiple nationalities to represent countries involved in World War Two, with the evil Dr Josef Heiter Heiter meaning "cheerful" in German representing the Nazi German psyche. Finally, Six was also inspired by the previous cinematic offerings from visceral directors David Cronenberg and David Lynch, and also the Dutch iteration of the iconic reality series Big Brother. The Human Centipede 2 Full Sequence The sequel film took things to an even darker place, with much more graphic scenes and more disparate inspirations. Six decided to make the plot very meta it would focus on a fan of the first film who would then conduct his own sadistic experiments and punishments. The chief inspiration for this decision was Six's fascination with copycat serial killers, who usually start as fans of the original killer. The term copycat killer was coined after the killings by iconic and mysterious serial killer Jack the Ripper sparked a number of similar murders. Catherine Eddowes - a victim of Jack the Ripper. Image Cornwell Entertainment,Inc.CEI The film Natural Born Killers starring Woody Harrelson is often blamed for sparking copycat killings, after being loosely based on serial killers Charles Starkweather and Caril Ann Fugate. Up to 12 murders were linked with being inspired by that film, including teenage couple Benjamin Darras and Sarah Edmondson, who described themselves taking LSD and watching the film on repeat before killing 3 people and paralysing another. The creepy villain of the sequel film. Image Six Entertainment Company The character of Martin Lomax is a short, obese man who is mentally challenged and becomes obsessed with the first film, before setting out to create a larger human centipede than the 3 people sewn together in the first film. Read more Read more inspiring features The Human Centipede 3 Final Sequence The last film saw Six want to return to the theme of the original joke that inspired the film series punishment. It was set in a prison where a psychopathic prison warden and his accountant each played by the actors behind the villains of the first two films who decide to inflict brutal torture upon the inmates of the prison - including mass castration, cannibalism, genital mutilation and a massive five-hundred person sized centipede. The film had a much more satirical tone, but this was one of the many aspects of the piece that critics and fans slammed. With the Governor played by Hollywood star Eric Roberts approves the torture as being "what America needs" at the end of the film, things enter a more dystopian territory - as we see extreme values in corporal punishment come bleed into culturally-approved torture. Corporal punishment is always a controversial topic, but its pros and cons were dealt with no sympathy here. Guantanamo Bay's detention centre. Image Joe Raedle/Getty Images Six likely saw inspiration in infamous prisons that were the site of torture, such as the US base at Guantanomo Bay in Cuba, and of course the Nazi concentration camps that were the chief basis of the first film. We expect Tom Six's next film to be just as provocative. The Onania club will be released later this year.