It is a real-life art world mystery that began with a hunch that a painting holds a 500-year-old secret.
Until now, it was believed to be a non-descript German portrait from the 1800s. But one art dealer and a team of investigators suspected something more.
They saw in this small picture the hand of Leonardo da Vinci -- dubbed by many the greatest artist of all time, the man behind the "Mona Lisa," "Vitruvian Man" and "The Last Supper."
Canadian-born art collector Peter Silverman bought...Full Story