Sopranos actor Federico Castelluccio bought a 17th-Century painting worth millions, but he didn't know it until now. The actor who played Furio, a prized mobster Tony Soprano brought back from Italy, Federico Castelluccio has a keen eye for fine art.

Federico Castelluccio is a degree-carrying art collector. He is also an amateur painter and art lover. He followed a hunch that a painting he bought was incorrectly identified, and he called in the art experts.  The experts discovered and confirmed that the artwork is piece by Italian baroque painter Guercino, aka Giovanni Francesco Barbieri that was painted in the 1630s.

Castelluccio told the New York Post, "they (auctioneers) had no idea who painted this."

Giovanni Francesco Barbieri is considered a master of chiaroscuro, whicn is the treatment of light and shade.

Castelluccio found the painting at a Frankfurt gallery. Federico told the New York Post that it was a identified as an "18th-century Italian holy painting of Saint Sebastian." Castelluccio paid about $140,000 for it, including a restoration. Years later, Castelluccio discovered the artwork was worth millions.

Speaking about Federico, private art dealer Robert Simon told Yahoo News "He's always been very interested in the artist."

Castelluccio painted a portrait of Simon's dog in Guercino's style called  Mastiff Homage to Guercino (2010).

When Castelluccio showed the painting to University of Delaware art history professor David M. Stone, who told the Post. "I saw the painting a couple years ago. It was overpaintined and needed to be professionally cleaned and needed a lot of research, which he did himself. I invited Federico Castelluccio for dinner at my house in Philadelphia and he brought the painting,"

Stone an expert on the works of Guercino wrote the catalogue for the Turin exhibit, and was one of the researchers who authenticated the painting.