Art experts believe a new portrait by Leonardo da Vinci may have been discovered thanks to a 500-year-old fingerprint. The painting of the woman in profile -- now identified as La Bella Principessa and believed to have been created around 1496 by the legendary Renaissance artist. The painting of the young woman in profile was previously believed to be a German work from the early 19th century and has changed hands in recent years for around £12,000. But a growing number of leading Leonardo scholars agree the work is almost certainly by the Renaissance figurehead because it appears to have his fingerprint on it. Carbon dating and infrared analysis of Leonardo's techniques back up the theory. If the scholars are correct, it will be the first major work by Leonardo to be identified for 100 years and will be worth tens of millions of pounds.