Here’s some potentially bad news if you own a Caravaggio.

Chances are you acquired it when the Baroque master’s entire body of work numbered about 90 pieces. In 2010, his catalog expanded by slightly more than 1% when an unknown painting was discovered in the possession of Jesuits in Rome. Two years earlier, The Calling of Saints Peter and Andrew was added after curators for Queen Elizabeth II had it authenticated.

These discoveries pale in comparison to a recent find from a castle in Milan. After working for two years in secrecy, historians from the Brescia Museum Foundation claim to have unearthed 100 paintings and sketches by Michelangelo Merisi da Caravaggio.

Since the announcement came without warning, it created a storm in the art world. On Friday, the researchers published their findings on eBooks at Amazon. The announcement was met with immediate skepticism.

“I will wait to consult the complete research, but the drawings I’ve seen so far do not seem to me attributable to Caravaggio,” said Francesca Cappelletti told Reuters. Cappelletti  is an expert on the Lombardy master who was never consulted by the Brescia researchers.

“We must be very prudent,” said Cristina Terzaghi, the author of a book on Caravaggio. “These sketches were well known. I had myself seen them. Their research must be carefully studied and verified by the scientific community.”

Even the owners were skeptical.

The works were housed in a castle collection owned by the city of Milan. “The drawings have always been there, and have never yet been attributed to Caravaggio,” said Elena Conenna, the council’s spokeswoman for culture. “We’ll be very happy to discover it’s true. But it’s strange. They weren’t in a hidden place, they were accessible to all.”

If the Brescia team is correct, if the works are by Caravaggio, the entire collection could be worth more than 860 million dollars. Since it’s no longer as rare, your Caravaggio will probably be worth a little less….