Italy's most celebrated neoclassical sculptor was a cheat, an art expert claims this week. According to Maurizio Bernardelli Curuz, editor of Stile Arte, a fine art magazine, Antonio Canova did not create one of his most famous works, Venus Victrix, by allowing the evidence of his eyes to dictate the motions of his chisel. Instead, he made plaster casts of her breasts to obtain a degree of realism closer to the work of modern British artists like Marc Quinn and Damien Hirst than to the classical masters who supposedly inspired him. Venus Victrix, or Venus the Victorious, is one of the biggest draws in Rome's Galleria Borghese, is a portrait in white marble - covered in a thin layer of wax, to heighten the realistic effect - of Napoleon Bonaparte's famously racy sister, Pauline, one of the beauties of the age. She sprawls elegantly on a chaise longue, naked to the waist, her head propped on one hand. The draped wooden base of the work contains a mechanism to make the work rotate in front of the viewer.But Canova's innovations did not stop there, according to Mr Curuz. The artist, he claims, created unprecedentedly realistic breasts by the simple device of obtaining plaster casts from life. "The story begins with a piece of evidence straight out of a police drama," Curuz writes. "I have in front of me the plaster cast of the breast of Pauline Bonaparte ... The plaster provides evidence on the one hand of the softness of the skin [of Ms Bonaparte], and on the other the healthy weight [of the breast] which gives the plastic material on the lower part of the soft hemisphere its characteristic curve," he writes.The breast, in other words, is beautiful - but in a way that distinguishes it from the beauty of the classical tradition. "This is not, to sum up, the conventional breast of Greek statuary, connected to the evocation of a perfect, platonic ideal of woman. However sublime the form, it has something of the phenomenal about it, something concrete."The clinching fact, according to the critic, is the nipple as represented in the surviving plaster cast: instead of standing proud and round, he writes, it is "slightly squashed, giving the impression of two slightly parted lips."For Curuz this proves that Canova's illustrious model permitted the artist to slap wet plaster over her torso, in the interests of artistic perfection - but in stark contradiction of the traditions of classicism.Mr Curuz's claims are published on the magazine's website, in a taster for a fuller article in which he promises to stand them up.But he will have a fight on his hands. It did not escape the attention of Marco Vallora, a correspondent on La Stampa, that 2007 is the 250th anniversary of Canova's birth, and that a flood of Canova exhibitions and related events is about to be unleashed."There is nothing to be astonished about," he writes. "It is enough to announce a major exhibition, and promises of scandals and discoveries start to pour down. Then as soon as the exhibition opens, they all cease. It's punctual, scientific, like thunder after lightning, only in this case the thunder arrives first."The claims are pure hokum, Mr Vallora suggests. Where is the proof, he demands, that Mme Bonaparte allowed the artist to take such astounding liberties. "Letters? Documents? Proof?... I am dubious, not so much on account of the ban on using plaster casts... but, above all, from the point of view of social convenience."Would Pauline have permitted the sacrilege of the artist laying hands on her like that? Or, even worse, his assistant?"