Having taken my Archaeology Masters at York's King Manor and having spent a great deal of time in York Minster (professionally and otherwise) I thought I would have heard this story.

I'm not the sole authority, of course, but I can't find anything in academic literature about it and nor does it seem to be on any of the published tour literature. With that said the major academic journal works on St. William were published in the 1930s and 1950s and therefore predate his rediscovery in the 1960s and his subsequent relocation to the crypt.

The tours at York Minster are full of fascinating information and are usually correct but they naturally include some myth, legend and unproven titbits for the tourists. I wonder if this is a modern legend that will become part of the accepted mythical history?