maxb727 said:
Any reason the information couldnt be posted directly on here for anyone else who may be interested?
Because it involved personal friends' email addresses.
But on the whole, yes as far as i know governmental permission is required to just enter a cave in Greece, let alone try to discover new ones. And no it's not easy to gain permissions if you can't speak Greek (hence the personal contact details).
As Brains has pointed out, Jim Eyre describes well his exploits of trying to get permission to get down Provatina, up on the Astraka Plateau back in the 70's (i think!). It seems it wasn't easy then either.