The Idol judge took the stage during the reality Tv show's big finale to treat fans to a medley of her greatest hits, including Hero, Vision of Love, We Belong Together and Make it Happen, but a number of viewers flocked to Twitter.com during her set to question whether the artist was singing live when it appeared that her lips weren't matching the words of the songs.
One critic with the user name @entylawyer wrote, "Mariah Carey lip synched on a show where she judged people who are not allowed to lip synch. So disappointing", while @scott_thrill tweeted, "How is Mariah Carey going to lip-synch on a show about singing live? That's like the host of Intervention doing heroin during the show".
The negative response has prompted the singer's spokesperson to issue a statement about the performance to Eonline.com, which reads: "She ABSOLUTELY DID Not lip-sync. She performed Live in front of several thousands of people!!!!...
"No Lip-Syncing whatsoever! She did 3 takes and thrilled the crowd with singing little songs in between (commercials) that were Not part of her medley."