It was taken in the 1920s at a time when Hitler wanted to portray himself as a man of the people.
But after he came to power in 1933 he tried to suppress the embarrassing picture as it went against his image of a hardened, iron-fisted ruler.
The photo album was found in the former home of prominent Nazi Viktor Lutze by a British army officer who was billeted there at the end of the Second World War.
Lutze’s son, Viktor Jnr, served in the German army and the album contains a picture of him as a teenager with Hitler taken before the war.
Lutze, who was the leader of the notorious ‘Brownshirts’ – the paramilitary wing of the Nazi party – died in a car crash along with his daughter Inge in Potsdam, Germany, in 1943.
In the album there are numerous family photos of Lutze with his children and wife Paula.
Other snaps show the henchman being treated as a VIP at Nazi rallies. One picture shows him quaffing a goldfish bowl-sized glass of red wine.
The photos have now come to light by the son of the army officer who spirited them out of Lutze’s old house in Bevergern in western Germany in 1945.
The unnamed officer of the Royal Engineers brought them back to Britain with him after the war and it has been kept in his family ever since.
The photos are being sold by Hansons Auctioneers of Etwell, Derbys.
Adrian Stevenson, of Hansons, said: “The odd-looking picture of Hitler was taken long before he became the German Chancellor and Fuhrer.
“He is captured wearing an alpine jacket and lederhosen.
“It was an early propaganda image and Hitler looked like a peasant to try and create the image that he was one of the people.
“But when he came to power it was entirely the wrong image to portray and he didn’t want that image being used.
He thought that a photo of him with his knees on display would harm his image.
“He tried to suppress it and it was banned from use.
“Probably a few hundred of them were printed. It is very rare to come across these pictures today.
“This one came from the house of the high-ranking Nazi Viktor Lutze who was the head of the brownshirts.
“Had he survived the war Lutze would have been tried at Nuremberg and probably would have hung for war crimes.
“In 1945 a British officer of the Royal Engineers was billeted in his old house and he liberated these photos, shall we say.
“They have just been sat in a drawer for years and his son has decided now is the right time to sell them.”
Lutze died aged 52 and was given a state funeral in Germany, which Hitler spoke at.
The photos are being sold in four lots for about £50 each on March 19.