Martin Kemp, a Professor of History of Art at Oxford University who bought this chalk portrait in 2007 for $19,000 may soon find it worth as much as $100 million after finding what experts believe is Leonardo da Vinci‘s fingerprint in it.

Peter Paul Biro, the Montreal-based forensic art expert, examined the multispectral images and found a fingerprint near the top left of the work, corresponding to the tip of the index or middle-finger, and “highly comparable” to a fingerprint on Leonardo’s St Jerome in the Vatican (which, stresses Biro, is an early work from a time when Leonardo is not known to have employed assistants).

[Antiques Trade Gazette]