A work prominently featured in the British Museum's current "Treasures from Shanghai" exhibition, on view until March 27, has some questioning whether the museum has violated its own recently implemented guidelines about showing illegally looted works, according to the Art Newspaper.

The work, a bronze drum stand dating from 770–476 B.C. on loan from the Shanghai Museum, likely came from the tomb of a ruler but is unknown to archaeologists. It appears to have been illegally excavated within the past few years.

In China, important antiquities are sometimes purchased from illicit sources and given to museums in order to ensure that they're kept in the country.

Shanghai Museum curator Zhou Ya says the drum stand is "unlike anything else known from China."

Last September the British Museum approved a policy stating that it will not "lend to any exhibition which includes objects that have been... illegally excavated” and will observe "the same principles" in requesting loans.

Speaking about the drum stand, a representative of the museum said that he was “not aware that the object was illegally excavated” and that the work is “incontestably a Chinese object."

"It left with Chinese government approval, and the loan was approved by the Cultural Relics Bureau,” the spokesperson said.

Still, some have expressed concern over the loan, according to the newspaper. Colin Renfrew, a professor of archaeology and a British Museum trustee until 2001, said last month that “a little more due diligence in this case might have been useful.”