Mentioned earlier here. Georgina Adam and Anny Shaw have lots more detail in the Art Newspaper, including this from New York Judge Charles Ramos during a January court hearing:
"“I have never seen an industry more ripe with fraud and misconduct than the art business. To say there’s such a thing as artistic ethics is an oxymoron. Most of the cases I’ve had involving art dealers involve fraud outright. Just plain old fraud. This is not a nice business."