They believed they were safe but a few blood drops betrayed them: 15 years after a daring robbery at a French jewellery store, the four alleged perpetrators have been found — in Serbia.

The Belfort job had all the hallmarks of a "Pink Panther" operation, the modus operandi used by an international jewel thief network of Serbs and Montenegrins responsible for some of the most audacious robberies of the past two decades.