For decades academics and historians have pondered how and why Adolf Hitler became history’s biggest monster. But another narrative about the German leader has been around for almost as long: The myth of his disfigured genitalia.

On Monday, that claim resurfaced when news outlets around the world reported the German dictator had a micropenis, citing old research made by two historians in the book, Hitler’s Last Day: Minute by Minute, which was published in the middle of 2015.

“Hitler himself is believed to have had two forms of genital abnormality: an undescended testicle and a rare condition called penile hypospadias in which the urethra opens on the under side of the penis” writes Jonathan Mayo and Emma Craigie in Hitler’s Last Day. But, when interviewed by the Independent, Craigie said that it was a “leap” to suggest the Führer had a micropenis because he suffered from hypospadias.

Speculation about Hitler’s undercarriage is far from a new thing, however. It has been in existence at least since WW2, when troops made reference to his alleged monorchism in the song ‘Hitler Has Only Got One Ball,’ sung to the tune of Colonel Bogey:

The historic claim, which lived on in the form of a playground rhyme, was given new credence by British newspaper The Sun in 2008. The tabloid claimed that a document surfaced with the alleged testament of a battlefront medic, Johan Jambor, who was serving with Hitler during the 1916 battle of the Somme.

The story of the medic, who died in the 1980s, was related to the Sun by his friend Blassius Hanczuch, who described the moment when Hitler realized he lost a testicle in the battle: “His abdomen and legs were all in blood. Hitler was injured in the abdomen and lost one testicle. His first question to the doctor was: ‘Will I be able to have children?’.”

But Ron Rosenbaum, who has written several books about Hitler, questioned the veracity of the Sun’s claims saying that they provided no evidence to corroborate the witness’s story. “It is true that Hitler was wounded during the battle of the Somme” he wrote in Slate in 2008. “The most reliable recent biographer Ian Kershaw says he was wounded in “the left thigh,” not “the abdomen” as the Sun‘s perhaps mythical medic Jambor has it”

Furthermore, the claim seemed to contradict the account of Eduard Block, Hitler’s childhood doctor, who according to the Telegraph told U.S. interrogators in 1943 that the fascist’s genitals were in fact “completely normal.”

However, like any good conspiracy theory, the story has proved unkillable and on Dec. 2015, German professor of history Peter Fleischmann, from the University of Erlangen, claimed to have medical records proving that Hitler had an undescended testicle on the right side.

The documents were apparently made in 1923, reports the Telegraph, when Hitler was examined by a prison doctor following his failed first attempt to seize power in the Munich Beer Hall Putsch.

Whatever the truth behind the rumors, dwelling on tales of Hitler’s damaged, sized-down or missing genitalia is the wrong way to analyze the true nature of his brutality and criminal pathology, according to Rosenbaum. The real appeal of the story, he writes, is the idea that “it wasn’t the Western democracies who failed to save the world from Hitler with their fatal appeasing weakness….Hitler wasn’t the fault of the German people; he was the fault of this one German, Johan Jambor—and the one missing ball.”

Get our History Newsletter. Put today's news in context and see highlights from the archives. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.