(ANSA) - Florence, September 11 - Researchers digging for the remains of the Mona Lisa said Tuesday that they've uncovered what could be the skeleton of another model used by Leonardo da Vinci in creating his famous painting. Researchers, who have been digging in the basement of a former convent in central Florence where they believe Lisa Gherardini Del Giocondo was buried, will hold a press conference Wednesday to explain their latest findings. This latest discovery ''is very important, and different from what has emerged so far,'' said Silvano Vinceti, the scholar responsible for the investigation. For months, he has led a team working near the altar in the basement of the former convent of St. Ursula, where it's believed Mona Lisa, a Florentine noblewoman, was buried in 1542. Other skeletons have been discovered there which Vinceti says may be connected with the famous painting. One of those may be the Florentine noblewoman Maria del Riccio, who could have been another model for Leonardo. Vinceti, now head of the National Committee for the Enhancement of Historical, Cultural and Environmental Heritage, has stressed that his search is based on research of historical documents that have led him to this point. Leonardo sleuth Giuseppe Pallanti published a book in 2007 arguing the former convent ''must be'' the last resting place of La Gioconda, as the Italians call the Mona Lisa because of the surname of her husband, del Giocondo. La Gioconda is believed to have joined the Ursuline nuns in old age. It has frequently been suggested that del Giocondo commissioned Leonardo to paint his Mona Lisa (mona is the standard Italian contraction for madonna, or ''my lady,'') to mark his wife's pregnancy or the recent birth of their second child in December 1502.