I've sometimes wondered if there is a connection to the body you find right at the bottom of the dungeon. But, I somehow doubt it... unless the Telvanni have devised a way to preserve bodies so that they don't decompose....
Hmm.. Maybe the Telvanni, being prone to necromancy, have a secret passion for embalming
Seriously, I've looked around several times, and there just doesn't seem to be anything conclusive out there on the identity of Uvirith. Makes me wonder if the developers had intended to add something to the story but it was omitted or forgotten..
That's certainly the case with a number of things in the game...