. >> reporter: from ohio, professor amaer al azzam helps oversee a team of monuments men, volunteers working on the other side of the front lines, even undercover in isis-held territory. but 92 matter how hard they work to protect and track these items the global trade in looted antiquities is booming, fueled by demand from buyers abroad, as far away as london. >> everyone here is probably going to be affluent and purchasing expensive things -- >> reporter: professor mark altawil is an expert in what he calls blood antiquities. >> the scale is massive. it's certainly funding a lot of armed groups or armed groups in the conflict. that to me is the great tragedy of this. it's leading to the utilization of the past to destroy the present. >> what prices are we talking about? >> large mosaics can sell for hundreds of thousands of dollars. certainly these objects have tremendous value. >> reporter: he says most of the illegal trade occurs online. >> it says "syrian." >> and other objects could be from syria. >> reporter: though not all items can be traced to looting, he wants the sale of