Isleworth Mona Lisa
According to Leonardo's early biographer Giorgio Vasari, Leonardo had started to paint "Mona Lisa" in 1503, but "left it unfinished". However, a fully finished painting of a "certain Florentine lady" surfaced again in 1517, shortly before Leonardo's death and in his private possession. The latter painting almost certainly is the one that now hangs in the Louvre. Based on this contradiction, supporters of the authenticity of the "Isleworth Mona Lisa" claim it is the unfinished "Mona Lisa", made at least partially by Leonardo, and the Louvre "Mona Lisa" a later version of it, made by Leonardo for his own use.
Isleworth Mona Lisa
In October 2013 Jean Pierre Isbouts published a book titled "The Mona Lisa Myth" examining the history and events behind the Louvre and Isleworth paintings and confirmed the latter's attribution to Leonardo. A companion film was released in March 2014. In April 2014, Albert Sauteur examined the perspective used to execute the "Isleworth Mona Lisa" and the "Mona Lisa" in the Louvre, and concluded that Leonardo painted both works. In July 2014 "The Mona Lisa Mystery" premiered on the PBS television station's series "Secrets of the Dead". This documentary investigated, at length, the authenticity of the Isleworth painting.