BEVERLY HILLS, Calif. (ACNI, AP) - As the pressure heightens to repatriate national treasures to their nations of origin, auction houses are increasingly in the position of having to assure potential bidders of their adherence to the law governing the sale of such items. Isadore M. Chait, president of I.M. Chait Gallery & Auctioneers, Beverly Hills, has issued a statement guaranteeing the legality of Chinese artifacts in his company's July 12 sale that are affected by the 2008 Memorandum of Understanding (MOU).

The most useful tool in tracking the background of an Asian antique is provenance and an auction house's own prior experience with a given object. Chait said that in the case of his next auction, for instance, many of the items were purchased from his gallery in previous years. Others came from documented private collections or estates, or were previously the property of reputable institutions, such as the Asian Art Museum of San Francisco.

By issuing assurances of legality, Chait hopes to mitigate what he views as the "potentially destructive impact of the MOU on the American market for Chinese art and antiquities."

The MOU covers Chinese items dating from Paleolithic Period (75,000 B.C.) through the end of the Tang Dynasty (A.D. 907). It also applies to wall art and monumental sculptures that are at least 250 years old.

The agreement, which became effective in the waning days of the Bush Administration, allows such works to be legally imported only if Chinese officials issue a valid certificate of export or if they left China before January 16, 2009.

The MOU was created in an attempt to stop illicit trafficking in Chinese art, but only the United States participated in the accord. This could have "potentially damaging effects on legitimate collectors, scholars and dealers (in the U.S.A.)," Chait said. "It could also send prices on banned periods skyrocketing."

The list of Dynasties falling with the guidelines of the MOU are:

Some would argue that politics and the greater landscape of Chinese-U.S. commerce were behind the Bush Administration's 11th-hour compliance to the MOU. But where the United States led, none were to follow, as became evident in Christie's Feb. 23-25, 2009 auction in Paris of the Yves St. Laurent & Pierre Bergé collection. Beijing demanded that Christie's remove two 18th-century animal fountain heads from the sale and to return them to their country of origin, China.

The sculptures - a rabbit and a rat - were part of a dozen animal heads from the Chinese zodiac that formed an elaborate water-clock fountain designed by Jesuit missionaries for the Old Summer Palace on the outskirts of Beijing. The two animal heads in Christie's sale had disappeared when French and British forces sacked and burned it at the close of the second Opium War in 1860. Chinese view the devastation of the palace, the country residence of emperors which was full of art treasures, as a national disgrace.

A group representing Beijing went to court in an attempt to stop the auction of the imperial fountain heads, but a French judge ruled against them and even ordered them to pay euro1,000 ($1,275) in fines to both the auction house and to the firm of Pierre Bergé.

At the time, a defiant Bergé told the media he had no intention of "giving these heads to the Chinese government ... Rather, I would recommend that the Chinese, instead of getting worked up over the heads, worry about human rights."

The fountain heads were sold at auction to a telephone bidder for $36 million. Later it was determined the buyer was a sham bidder whom some suggested had been acting on behalf of Beijing. The Chinese government denied any involvement with the sham bidding but moved swiftly to punish Christie's with tightened customs rules. After the Paris auction, China's State Administration of Cultural Heritage announced it would order tighter inspections of all cultural relics that Christie's sought to remove from or ship to mainland China going forward, requiring certificates of legal ownership and documented details of ownership history. Items lacking sufficient documentation would be denied entry or export, the State's spokesperson said.

Beijing vows to continue its efforts to recover similarly looted Chinese relics through "all necessary channels."

"People in government, academia and even on a local level have long been trying to get all these items back," said Tracey Lie Dan Lu, director of the Centre for Cultural Heritage Studies at the Chinese University of Hong Kong. "Now the Chinese government is making it more clear, sending the message out to the world so that people will pay more attention to this issue."

Catherine Saunders-Watson (Auction Central News International) and Associated Press contributed to this report.