A mysterious tunnel under construction has been discovered near a prison in southernParisduring routine electrical works, although police sources said it did not appear to be part of an escape plan.

The discovery was made on Tuesday by a technician from Enedis, which manages the electricity distribution network inFrance, who was working in a well for electrical connections about 450 metres from La Santé prison, a police source said.

Bags of rubble and a bed had been found at the scene, the source added.

Guillaume Durand, an official in the French capitals 14th district, where the prison is located, said he doubted that an elaborate escape plan had been in the works.

Its a four-metre tunnel, in a cul-de-sac on rue de la Santé, but more than 500 metres from the prison, he said.

Police believe that it is, rather, something which would aim to facilitate the arrival at the catacombs, therefore the work of cataphiles, he said, referring to clandestine catacomb explorers.

He said officials had sent an engineer to the site to fill in the hole.

ThePariscatacombs, a massive underground ossuary, are one of the citys most popular attractions and lure about 500,000 visitors a year. (AFP)