London: A self-portrait long believed by its owners to be a copy has now been identified as an original work by Leonardo da Vinci, after investigators found three fingerprints on the artwork.

A team led by Luigi Capasso, an anthropology professor at Italy’s Chieti University, along with forensic specialists, said the prints were compared with fingerprint traces seen on another da Vinci work and were found to match.

Researchers also sought support from art experts and historians, and carried out scientific checks including radiocarbon dating and pigment analysis to strengthen the attribution.

According to the team, the tests indicate the work may have been created between 1478 and 1520. Investigators also reported finding da Vinci’s signature and markings on the piece.

Capasso noted that the group approached the question through scientific and forensic methods rather than art-historical interpretation, focusing on the fingerprint evidence as a key indicator.