The Underground Passages of Rennes-le-Château, and the Crypt of the Church of Mary Magdalene were dug by the restaurateur Noël Corbu during the 1950s and 1960s, before he left Rennes-le-Château in 1964 when he sold the Saunière estate to Henri Buthion, moving to Château of Saint-Félix-Lauragais just before his death in 1968, though he was buried in the village cemetery. Also, it is quite normal for any church to have a burial crypt, there is nothing “unusual” about this.

Corbu's digs beneath the church of Rennes-le-Château still remain to this very day, and the Believers and Rennies are without any shame. Corbu only told the story to attract custom to his restaurant – but there is no “written confession” (how could there be?) – Corbu's “treasure story of the Billionaire priest” only first began appearing after the death of the former priest's housekeeper, Marie Denarnaud, in 1953.

These are all well-known facts to the Believers. But they continue with their contes de fées; which is only one conspiracy theory amongst literally thousands of others.

There is a Rational Explanation with a prosaic explanation to every Conspiracy Theory.