Researchers in Italy said Monday they may have found traces of a Leonardo da Vinci work hidden under a fresco at the Palazzo Vecchio in Florence.

The research team is being led by San Diego State University art professor Maurizio Seracini, who has spent decades searching for The Battle of Anghiari, a fresco by Leonardo depicting a 15th century battle between soldiers from Florence and Milan.

It’s known that da Vinci began the artwork in Florence's Palazzo Vecchio in 1505, but never finished it. Another painter, Giorgio Vasari, is believed to have placed a wall in front of it around 1550 and painted a new mural over top.

Researchers have drilled tiny holes in Vasari's The Battle of Marciano and retrieved paint from a work discovered beneath. Their analysis concluded that the black pigment found is the same paint used in the Mona Lisa.

Research not conclusive

However, further analysis is needed before the researchers can say conclusively that they have found Leonardo's work, according to Seracini. The researchers have been given the go-ahead to use infrared and other technology to look behind the existing Vasari mural.

"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,"  Seracini said on Monday.

Leonardo's The Battle of Anghiari was praised by his contemporaries as a fine work. Flemish baroque painter Peter Paul Rubens drew a famous copy of it that shows a bloody scene of terrified men and horses.

Seracini said he believes Vasari recognized the quality of the work and arranged to build a new wall before creating his own painting. Vasari's mural includes a soldier holding a small flag bearing the words: "He who seeks, finds."

Some art scholars have opposed the research because of the damage done to Vasari's mural.

Italian art historian Tomaso Montanari has said any painting from da Vinci's time could have similar chemical composition to pigments he used and that there is nothing to link the discovered work to the master painter.