Does Leonardo Da Vinci's The Battle of Anghiari lie in Florence's town hall?
Produced in 1504 and unseen since renovations took place in 1555, the fresco is regarded as one of the great remaining mysteries of the art world.
And its "discovery" has sparked a battle of its own between two groups of art experts.
Maurizio Seracini, a researcher at the University of California, San Diego, and the head of the project, claims that the long lost work lies beneath Giorgio Vasari's 1563 effort The Battle of Marciano in Val di Chiana.
Following the drilling of six small holes in Vasari's fresco, tests have found that the black pigment that lies behind it closely resembles that used in Da Vinci's Mona Lisa and St John the Baptist.
"These data are very encouraging," commented Seracini.
"Although we are still in the preliminary stages of the research and there is still a lot of work to be done to solve this mystery, the evidence does suggest that we are searching in the right place," he added.
Dissenters have suggested that the work that lies beneath could easily have been produced by another painter, and a petition has begun to put a stop to the drilling.
Da Vinci is the pinnacle for many collectors' aspirations. Microsoft founder Bill Gates is the current owner of the Codex Leicester - a coveted collection of Leonardo Da Vinci's writings - which he bought for £19m in 1994.
"Discovered" paintings are among the most exciting pieces at auction.
A Young Girl in Profile in Renaissance Dress, sold for $19,000 at Christie's New York in 1998, is now valued at $100m after investigations suggested that rather than being a 19th German work, it was in fact a Da Vinci.
A Michelangelo drawing, Study of a Mourning Woman, sold for £5.9m in 2001, having been unearthed following 250 years of obscurity in North Yorkshire.
You can discover some rare pieces of your own among Paul Fraser Collectibles' fine array of artwork for sale.