The copy was most likely made by da Vinci's student Francesco Melchi. "It seems as if the two painters were in the same studio, in front of the same canvas" said the deputy director of the Prado Gabriele Finaldi.

Prado and art historians did not pay much attention to the painting, overtaking him as one of Gioconda's fairly later copies. Until yesterday, around the female figure in the copy there was nothing but a dark setting - in contrast to the "unbalanced" landscape of the original.

But preparing the painting for a relevant exhibition at the Louvre in Paris, which houses the real Mona Lisa, conservators removed the "dark veil" and discovered a landscape almost identical to that in the original work.

In Prado's copy, the face of the female figure is seen without the "cracks" of the original and the colors are much more vivid. An interesting difference is the eyebrows, which are entirely missing from the original.