You don't need to authorise the name you're publishing music on in iTunes, I assume. People were uploading old Marina music to iTunes that wasn't official. It's possible to do. However they do it, I don't know.
I don't think copyright is any indication though. I just checked my Electra Heart single which I still have downloaded and it has a copyright on it and it was confirmed fake. Who knows.
If it is fake, you can get a refund. I got one for Electra Heart, so it's no worry.