MOSCOW (AFP) - A stolen silver medallion that once belonged to the family of Russias last tsar was on Thursday returned to Russian authorities by the United States, the US Embassy in Moscow said. The medallion disappeared from the collection of the State Hermitage Museum in Saint Petersburg and was spotted on an online auction site by Russian investigators, who notified US officials, the embassy said. Based on this information, Special Agents of the US Immigration and Customs Enforcement were able to locate and recover the medallion, the embassy said in a statement, without providing other details of the operation. The small medallion decorated with a portrait of 18th-century tsar Peter the Great had belonged to the family of Russias last monarch, Nicholas II, who was murdered by Bolshevik revolutionaries in 1918. It was one of 221 items that were discovered to have been pilfered from the Hermitage during a 2006 audit of its collections. Only a small number of those items have been recovered, according to Russian media reports. In 2007 a Saint Petersburg court sentenced a man for stealing 77 artifacts from the museum worth over half a million dollars. The man had colluded with his wife, a Hermitage curator who died in 2006, to steal the items.