Its easy to see why art theft has historically been pretty popular: works of art worth millions are hung up for public inspection, are highly sought after, and are lightweight and easy to conceal. While most high-profile museums now have complex security systems, there always has and indeed there may always will be both the temptation and the demand for stolen works of art. This is the story of some of the most audacious, cunning and expensive art thefts ever.

Part 2: The World's Biggest Heist
When the Isabella Stewart Gardner Museum in Boston was robbed in 1990, it was the biggest art theft in history. Up to $500 million worth of art was ripped from the walls of the gallery in a single night, including rare masterpieces by Vermeer and Rembrandt.

Sixteen years later, no one has been charged for the robbery and the priceless paintings are still missing. The robbery went down in criminal folklore generating countless rumours and theories about who did it and where the paintings were. While some believe the paintings are still in America, others are convinced that Boston gangster, James Whitey Bulger, was behind the robbery and had the paintings shipped to Ireland from where the recovery of the haul would for many years have had to have involved an elaborate international deal involving Irish paramilitaries.

The Isabella Stewart Gardner Museum is one of the most eccentric in America. It houses the fabulous collection of wealthy socialite Isabella Stewart, whose will stipulated that the collection should remain exactly as she left it. For that reason none of the paintings was insured and where the stolen paintings once hung there are now just empty frames. The FBI have got nowhere in their search for the robbers or the paintings but a succession of former criminals and policemen, enticed by a $5 million reward, have been on the trail ever since.

For years one of them, William Youngworth the Third, an art dealer and thief, has claimed that he could get the paintings back but no one knows whether he can or whether his claim is a hoax. This documentary shows how the thieves pulled off the Boston heist and examines the Irish connection that might one day lead to the recovery of the priceless works of art.

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