Objects, gold or silva, jewellery, because you can melt down or dismantle a piece ofjewellery. and then these things disappear on the black market and sometimes even on the legal market. black market and sometimes even on the legal market. we may never know the legal market. we may never know the true scale the legal market. we may never know the true scale of the legal market. we may never know the true scale of the the legal market. we may never know the true scale of the damage - the legal market. we may never know the true scale of the damage to - the legal market. we may never know the true scale of the damage to this . the true scale of the damage to this priceless collection. but tonight the largest museum in the world is in crisis. with me now charles saumarez smith, former director of the national gallery, the national portait gallery and chief executive of the royal academy of arts. and christos tsirogiannis, archaeologist and antiquities trafficking expert who works w