Satellite images reveal the extent to which sites of important historical interest have been looted in Syria. Some of these are in areas controlled by Islamic State where looters are believed to pay a tax to allow them to operate. Iraqi military say evidence from a senior IS member revealed the group is making millions of pounds from the trafficking of looted antiquities Simon Cox investigates the global trade in stolen artefacts and traces smuggling routes through Turkey and Lebanon and onto the international antiquities market. He hears concerns that dealers and collectors are not doing enough to verify the provenance of ancient works of art and asks whether the authorities in the UK and elsewhere are doing enough to prevent the trade. Why, for example, does the UK remain the most significant military power not to have ratified a UN convention to protect cultural property during armed conflict? Reporter: Simon Cox Producer: Paul Grant.