Noël Corbu first claimed in 1962 on French radio that Ernest Cros made two discoveries in the region of Rennes-le-Château in 1928.

Viz: the following “artifacts”:

1)- a tombstone in the cemetery that bore the inscriptions “REDDIS, CELLIS, REGIS, ARCIS” and “PRAE-CUM”

2)- the “stone of Coumesourde” that bore the inscriptions “SAE”, “SIS”, and “P.S.” with “PRAE-CUM” – that formed a triangle, that also included what Corbu described a Templar Cross, bearing the additional words: “IN MEDIO”, “LINEA UBI”, “M SECAT” and “LINEA PARVAT”

Corbu claimed that Ernest Cros took the “stone of Coumesourde” with him when he went back to Paris. An appeal was made by the press to the general public for further information about its whereabouts with negative results.

To date, nobody has been able to confirm Corbu's claims about Ernest Cros, or the authenticity of the “artifacts” (Ernest Cros would have been 71 years old in 1928 when he allegedly made those discoveries).

Corbu made references to the Knights Templar in relation to the “stone of Coumesourde”.

Ernest Cros and Abbé Maurice-René Mazières were friends. Abbé Mazières had an article about the Knights Templar published in 1962 – and the name given at the top of its list of acknowledgments was Ernest Cros. Perhaps this was where Corbu's ideas originated.