Two historians have claimed that they have proof that German dictator Adolf Hitler suffered from an embarrassing secret medical condition, according to The Telegraph.

In their new book, “Hitler’s Last Day: Minute by Minute,” historians Jonathan Mayo and Emma Craigie claim that they have discovered medical records proving that the fascist dictator had a condition known as hypospadias, which results in abnormally small and deformed genitalia, sometimes referred to as a “micro-penis.”

“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,” Mayo and Craigie wrote.

Recently, a German historian also claimed that he has evidence that Hitler only had one testicle.

According to The Telegraph, “Hitler’s personal doctor, Theodor Morell, is also said to have diagnosed the Fuhrer with hypospadias and had prescribed him with hormones and amphetamines in an attempt to improve his sex drive.”

The Telegraph noted that a “bawdy” 1939 song claimed that “Hitler Has Only Got One Ball,” although — until recently — the claim was regarded as myth:

Hitler has only got one ball

The other is in the Albert Hall

His mother, the dirty b*****,

Cut it off when he was small

Hitler has only got one ball,

Göring has two but very small,

Himmler has something sim’lar,

But poor old Goebbels has no balls at all.