Though the stone had been painted over, he identified it as part of a stone used to cover the grave of an important person, such as a merchant or successful craftsman in about 1300. Graves of less important people were not marked in that era. Efforts are now being made to trace any documents showing where stone was taken from and when it was put into the building.
Pub owner Billy Nettleton said: "I've run the pub for ten years and walked past the stone many hundreds of times without noticing it. Nobody would ever have known about it, but for the smoking ban. I am really amazed."