Mona Lisa copy reveals new detail
The restored painting (right) offers more detail than the original (left)
A painting thought to be the earliest replica of Leonardo Da Vinci's Mona Lisa has been discovered at Madrid's Prado Museum.
The Prado said it did not realise its significance until a recent restoration revealed hidden layers.
The artwork features the same female figure, but had been covered over with black paint and varnish.
The painting is thought to have been created by one of Leonardo's students alongside the 16th century original.
There are dozens of surviving Mona Lisa replicas from the 16th and 17th centuries.
The Art Newspaper, which reported the discovery, said the "sensational find will transform our understanding of the world's most famous picture".
The original painting, which currently hangs at the Louvre in Paris, is obscured by several layers of old, cracked varnish.
However, cleaning and restoration is thought to be too risky because the painting is fragile.
The Art Newspaper said the removal of the black paint on the replica had revealed "the fine details of the delicate Tuscan landscape", which mirrors the background of Leonardo's masterpiece.
"Darkened varnish is also being painstakingly stripped away from the face of the Mona Lisa, giving a much more vivid impression of her enticing eyes and enigmatic smile," it added.
The Prado's copy also suggests the sitter in the painting was a woman in her early 20s - much younger than the Louvre's original appears to show.
As the replica remained hidden for so long under the overpaint, experts had believed it had been painted long after Leonardo's death.
But after using x-rays to analyse the original drawings underneath, conservators have concluded the work was carried out at the same time as Leonardo's original.
The museum presented its findings at a conference on Leonardo da Vinci at London's National Gallery.
There is still some restoration to complete on the painting but, once it is finished, it will be exhibited at the Louvre in March, allowing visitors to compare the two works.
^ this is crazy