Did authors really find huge trove of previously undiscovered Caravaggios? "Study of a Head" sketch found in the Sforzesco Castle in Milan has been attributed to the young Caravaggio by art historians Maurizio Bernardelli Curuz and Adriana Conconi Fedrigoli. ROME -- You wait ages hoping to discover a new Caravaggio, then 100 come along at once. Or do they? Two Italian art historians on Friday announced the discovery of dozens of works by Michelangelo Merisi, the real name of Caravaggio, who was famed for his chiaroscuro effect of dark space contrasting with light, vivid still life and then-scandalous use of models from the lower walks of life for religious scenes. The historians claimed the works by a young Caravaggio were among thousands of sketches and paintings by apprentices of Simone Peterzano, the 16th century painter for whom Caravaggio worked at the beginning of his career. Maurizio Bernardelli Curuz, the artistic director of the Brescia Museum Foundation, and his co-researcher, Adriana Conconi Fedrigolli, said they had scrutinized the collection in earnest and they found remarkable similarities with some of Caravaggio's known masterpieces. The Peterzano collection, which is kept in Sforzesco Castle, a Milan landmark, contains nearly 1,400 works. Until now experts had thought the collection contained only works by Peterzano, Bernardelli told The Associated Press. Painting at center of Caravaggio mystery unveiled "Evidently no one entertained the hypothesis that there were works" by his pupils, including future star artist Caravaggio, among the drawings, he said. Bernardelli and Conconi did not respond to requests for comment from NBC News. Only some 90 paintings by Caravaggio, who died in 1610 in his late 30s after a turbulent life, were thought to exist. So if proved authentic, the body of work would be worth a enormous amount -- as much as $900 million, some experts estimate. But did Bernardelli and Conconi really unlock the secret to the early Caravaggio? Luca Bruno / AP Tourists visit a yard of the Sforzesco Castle, in Milan, on Friday. The castle hosts an art museum where sketches by mannerist painter Simone Peterzano are preserved. Two Italian art historians claim to have discovered as many as 100 works, most of them drawings, by a very young Caravaggio in the collection long attributed to Peterzano. Some said that this is no great artistic find, and was instead a summer hoax. "We have known about these paintings for 50 years," Francesca Rossi, Art Curator at the Sforzesco Castle, told NBC News. Those two historians have never even been at the castle, nor did they see the paintings up close. All they did, Rossi said, was to request pictures of the paintings to be sent to them for research purposes. Nevertheless, on Friday the historians published their findings on a two-volume, 600-pages e-book in four languages. Authors' website Not enough, experts said, to give credit to an extraordinary claim that has the power to rewrite Italian art history.