Knoedler Gallery Again Accused of Fraud in New Lawsuit The once-grand Knoedler gallery has been accused again of selling a forged painting for $5.5 million that was attributed to an American master, in this case, the artist Mark Rothko. The Martin Hilti Family Trust, a charity created by the construction tool magnate of the same name and based in Liechtenstein in Europe, sued the gallery on Tuesday, stating that a forensic analysis of the work "Untitled (1956) " reveals that a particular red pigment used in the work "was not developed until the 1960s, years after the purported '1956' date of the work." This suit is the fourth filed in Manhattan federal court against Knoedler & Co. since it closed its doors in November 2011. It names Knoedler's owner, Michael Hammer, its former president Ann Freedman, as well as Glafira Rosales, the Long Island dealer currently being investigated by the F.B.I. for supplying this painting and dozens of others to Knoedler. One of the suits, filed over a $17 million work attributed to Jackson Pollock, was settled in October. A second suit was brought by Domenico DeSole, the chairman of Tom Ford's fashion firm, and his wife, Eleanore, over a $8.3 million work attributed to Mark Rothko, while a third was filed by John D. Howard, a Wall St. executive, over a $4 million painting attributed to Willem de Kooning. Mr. Hammer's lawyer, Charles D. Schmerler, said: "The Hilti complaint rehashes the same baseless claims contained in the prior lawsuits. Given the attention this matter has received, it is not unexpected to see copycat suits filed. We plan to aggressively litigate this case and expect to see Knoedler and Mr. Hammer fully vindicated. Ms. Rosales' lawyer has said that she has never knowingly sold any forged works. Ms. Freedman's lawyer, Nicholas Gravante Jr, provided a statement from her that said: "These paintings were exhibited in museums around the world and heralded as masterworks. This particular Rothko was featured at the Beyeler Foundation in 2002. The personal vendettas and professional jealously behind the attacks on the works and on my reputation should be obvious.