Ratings are up on the new season of NBC's hit singing competition 'The Voice,' but even if the additions of new coaches Usher and Shakira haven't had a negative impact on the show's performance, at least one of them might be making waves behind the scenes.

That's the gossip, anyway, as reported by talk show host Wendy Williams. Williams, who apparently picked up her information from the Star tabloid, alleged during a recent episode (embedded above) that there's a diva backstage at 'The Voice' this season -- and, as she put it, the guilty party is "Usher, of course!"

Williams went on to allege that Usher's co-judge Adam Levine is "tired of Usher's diva-like behavior," although as she noted, the report's suggestion that "Levine is friendly to everyone backstage but Usher" suggests that the diva-like behavior in question might be stemming from Levine. Regardless, Usher is apparently showing up late and insisting on being "catered to like he's the top dog on the show."

According to Williams' sources, this type of thing is nothing new for Usher; she went on to tell the story of a Chinese billionaire who tried to hire him to perform at a birthday party, only to be presented with a list of demands that included luxury accommodations (such as a private plane and penthouse suites) for the singer and his entire entourage, on top of his already-generous $1 million fee. In what Williams regarded as a hilariously ironic twist, the spurned billionaire decided to hire Levine instead.

Fact or nasty rumor? Only Usher knows for sure. In the meantime, we're waiting for gossipy reports on Wendy Williams' backstage behavior.