A hotly debated cast of an equestrian sculpture that some believe is linked to Leonardo da Vinci was estimated to sell for between $30 million and $50 million at auction last night. Instead, it flopped. 

The object—which was offered without a reserve, or minimum price—was the star lot at a sparsely attended Guernsey’s sale hosted at New York’s Pierre Hotel. Bidding started at $10 million before the auctioneer came down to $8 million. But no offers came in. The piece remains available for sale privately. 

The sculpture, titled Horse and Rider, is a contemporary bronze cast of a beeswax model that some believe to have been carved by Leonardo around 1510. It’s said to depict Charles d’Amboise, the French governor of Milan from 1503 to 1511 and a prominent patron of the Renaissance master. The original, proponents claim, would have been used as a model for a larger, unrealized monument. But whether or not that 10-inch statue was actually done by Leonardo has long been the subject of debate. 

“In my opinion, this wax model is by Leonardo himself,” wrote Carlo Pedretti, a noted Renaissance scholar who has authored numerous books on the artist, in a 1985 letter of authentication. 

Others don’t share Pedretti’s certainty. 

“It seems to me not credible as a Leonardo sculpture,” Martin Kemp, a Leonardo expert and art historian at Oxford University, told Bloomberg. The object “has none of the characteristics of understanding horse anatomy and Renaissance armor that you would expect from Leonardo.”

Another scholar was even more direct. “Sometimes a work is so ridiculous and impossible that a scholar like me feels authorized to speak,” said Francesco Caglioti, a professor at the Scuola Normale Superiore di Pisa in Italy. “This thing has nothing, nothing, nothing to do with Leonardo. I can’t imagine it was done before the late 19th century. It looks like a revivalistic work by the hand of somebody who tried to imagine a Renaissance horse and rider.”

After centuries circulating through private collections in Europe, a London-based antique dealer purchased the work in 1985. Noting the damage it had sustained and the instability of its material, he had a latex mold made of the object. 

Two years later, the mold was purchased by collector Richard A. Lewis, who, in 2012, used it to make the bronze facsimile offered up last night at Guernsey’s. Lewis also made 70 additional bronze casts in four different patinas, which he sold for between $25,000 and $35,000 in successive years.

The $30 million to $50 million Guernsey’s estimate—lofty by any stretch, considering the work was a contemporary cast of an object that might be by Leonardo—was set by Brett Maly, a Las Vegas-based appraiser known for frequent appearances on History Channel show “Pawn Stars.”