Hmmm, sounds like a tricky one, what you should do is e-mail the host, and ask for a read receipt (just so you know if they actually read it) , if they don't reply, contact them again and say you have evidence that they are allowing a site to resolve on the company servers, even though the site breaks several federal laws, make sure they know that if they are found to be knowingly hosting an illegal site, they can be brought up on charges also, that should cause a stir, and a certain response, and i have no doubt that they will swiftly analyze the offending site, and take swift action, if that doesn't happen, give the details of the host to ALL of the music companies that are involved, M.O.S, (based in liverpool?) if i am not mistaken, have a long record of law suits against internet piracy.
Forgive me if i have repeated myself several times in this reply, i am just logging off after an extended log analyzing run (7 hours).
i hope that this gave you some kind of help, and good luck.
Simon