Cheater

A few days ago, I was told by a friend that there would be a game tuesday (tonight). This is a home game i've been to about 3 or 4 times, and while the play isn't good (splashing, folding out of turn) I generally keep a steady winrate. He also suspects one of the guys there to be cheating. The reason he told me this was after he claimed to lose on consecutive 1 to 47, 2 to 47, and 4 to 47 shots while that guy was dealing (fairly obvious), and similar feats a few days later. He knows that I can spot people bottom-dealing much better than anyone else there, which is what he thinks he's doing.

The question I have is this: If (When) I spot this guy cheating, how should I go about with it? I'm thinking of saying something like "I'd appreciate if you dealt from the top of the deck and kindly quit cheating." I'm not sure.

Suggestions?