[Bernard Frischer, a professor of archaeology and classics, is the director of the Virtual World Heritage Laboratory at the University of Virginia.]

THIS year saw the end of the five-year-long trial here of Marion True, a former antiquities curator of the J. Paul Getty Museum in Los Angeles. The case against her — for the purchase of art allegedly looted from Italy — petered out inconclusively when the Italian statute of limitations expired.

The Getty is hardly the only American institution to be accused of buying art of dubious origin. In recent years, the Metropolitan Museum of Art in New York, the Museum of Fine Arts, Boston, and the Princeton University Art Museum have all returned contested works of art to the Italian authorities.

Even when museums have the best of intentions, some of the works they buy have passed through the hands of underground suppliers. It’s hard for museums to avoid the black market partly because there is so little legitimate excavation going on that can yield new finds. Illicit trade in antiquities, therefore, drives prices up and encourages looters to raid unprotected sites.

Sadly, when an object is taken from its original site without documentation, context is lost. And in archaeology, context is everything: it tells us an object’s age, its likely place of manufacture and its everyday use. This lack of information makes it harder for collectors to determine if an object is fake, while even authentic works, in the absence of the context of their discovery, become mute witnesses to our irresponsible acquisitiveness.

But there is one thing museums could do that would put looters and smugglers out of business while uncovering more of the world’s cultural treasures at far lower cost: excavate archaeological sites themselves....