The bust is one of Berlin's top tourist attractions
The famous bust of Queen Nefertiti believed to be 3,400 years old could be a fake, according to an art historian.
Henri Stierlin, who has studied the subject for 25 years, claims the bust of the Egyptian beauty is a 1912 copy.
He suggests it was made on the orders of German archaeologist Ludwig Borchardt, who is credited with finding the treasure on the banks of the Nile.
A spokesperson for the Neues Museum in Berlin, where the bust is housed, was not available for comment.
Egypt has demanded the return of the bust since it went on display in Berlin in 1923.
Swiss-born Stierlin, the author of several books on Egypt and the Middle East, said: "It seems increasingly improbable that the bust is an original."
Stierlin said Borchardt had hoped to produce a new portrait of the queen wearing a necklace he knew she had owned and also carry out a colour test with ancient pigments found at the digs.
But when the copy went on display in December 1912, it was much admired as an original work by a German prince and the archaeologist "couldn't sum up the courage to ridicule" his guests, Stierlin said.
The historian said he based his findings on several points, including the fact the bust has no left eye, which "is an insult for an ancient Egyptian who believed the statue was the person".
He also said the shoulders were cut vertically while Egyptians cut shoulders horizontally, and that Nefertiti's facial features were accentuated in a manner resembling an Art Nouveau style.
Stierlin claimed it was impossible to scientifically date the bust because it was made of stone covered in plaster, whereas the pigments were "really ancient"
And he said French archaeologists present at the dig never mentioned the find, nor did contemporary written accounts.
Stierlin added that the archaeologist "didn't even bother to supply a description, which is amazing for an exceptional work found intact".
But earlier this year, newly-published documents suggested Borchardt used trickery to smuggle the bust back to Germany.
According to those documents, he listed the bust among his finds in Egypt, but described it as a worthless piece of gypsum and hid it in a box.
The Neues Museum, which is currently closed, will reopen in October, with a new room for Queen Nefertiti's bust.