After a four-year investigation, members of an international organized crime gang have been found guilty in the thefts of artifacts worth up to £57m ($79m). Fourteen men will be sentenced in April for the raids on museums and an auction house in the U.K.

Chinese jade and rhino horn were among the items stolen in Cambridge, Durham, Norwich and Lewes, East Sussex.

Durham University Oriental Museum, Gorringes Auction House in Lewes, Norwich Castle Museum and the Fitzwilliam Museum in Cambridge were some of the main targets. A group of 18 important jade pieces from the Fitzwilliam have not been recovered.

Detectives maintained that the stolen items could be valued up to £57m ($79m) on the "booming" Chinese auction market.