...please make a post in the PR forums.
Too many CMs make Beee a grumpy man.
If you really really don't want to go public ask yourself why not? You're not going to get a hard time for airing your suspicions in the correct place as after all, you're only trying to help.
Please include as much detail as possible regarding why you are suspicious. Transfer logs, forum links, chat conversations etc etc all go a long way to make it easier for us to confirm and deal with people who cheat.