Italian scholars claim that they have discovered the earliest known work by Renaissance polymath Leonardo da Vinci. On a self-portrait of Archangel Gabriel, an interesting detail has been unnoticed for nearly 600 years.

A painted glazed tile depicting the Archangel Gabriel was examined using infrared analysis. The result revealed a tiny signature painted in the angel's jaw line, with a date 1471, barely visible to the naked eye.

The glaze tile was found by descendants of the aristocratic Fenice family of Ravello, Italy. They did not know the origins of the piece but they realized it was something that shone a bit brighter than the other things they found when cleaning out the house. They thus brought it to the experts.

A digital reproduction of the signature that Italian scholars claim to have found on the angel's jawline

Ivana Rosa Bonfantino, a handwriting expert who has analysed countless samples of da Vinci's work, pointed out that the handwriting match was very close between different examples and the one on the tile, even though the artist's penmanship evolved over time.

The Annunciation (circa 1472 or 1473) is currently considered as the artist's earliest work

It would be the earliest surviving work by da Vinci if the authorship is verified. It would have been more than 500 years since the 18-year-old artist created it in 1471. Experts believe it offers insight into the artist as a young man.

Almost all authenticated works by Leonardo da Vinci are now in museum collections. Last November, the last Leonardo da Vinci painting in private hands, Salvator Mundi, was sold for a record-shattering US$450.3m at Christie’s New York. The buyer was later identified as the Abu Dubai government.