Embarrassed officials were at a loss to explain how Jean-Pierre Treiber, 45, a double murder suspect, managed to elude detection in the box he had built himself at a workshop in the high security prison of Auxerre, Burgundy.

With its hidden human cargo, the box was loaded with dozens of others onto a lorry for delivery to the Yonne region, southeast of Paris.

During the 100-mile journey, he broke free and leapt from the lorry. The driver only realised there was a problem once he had reached his destination, when he spotted a hole in the tarpaulin covering the boxes, some of which were flattened.