I've never personally seen anything to suggest there was such a thing.
Of course I've heard testimonials (which are certainly evidence) and assertions of belief. But the volume of them fall well within the levels that could be attributed to religious fervor or silliness or hoaxes. So I don't see a reason to believe it based on the info out there that I've come across.
I try really hard not to believe things because I believe them. I'm not always successful.