Mariah Carey's rep slams American Idol lip-synching rumors

Mariah Carey's spokesperson has vehemently denied rumours that the singer was lip-synching during her performance on American Idol on Thursday night.

The Idol judge, who took the stage during the reality TV show's big finale, treated fans to a number of her greatest hits, including 'Hero', 'Vision of Love', 'We Belong Together 'and 'Make it Happen'.

But many viewers took to Twitter, to question whether the artist was actually singing live when it appeared that her lips weren't identical with the words of the songs, Contactmusic reported.

A critic, called @entylawyer, tweeted that he was disappointed because the mum-of-two lip-synched on a show where she judged people who are not allowed to lip synch.

Another one, @scott_thrill wrote, "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 reaction pressed Carey's rep to issue a statement regarding her performance to Eonline.com.

"She ABSOLUTELY DID not lip-sync. She performed Live in front of several thousands of people!!!!...," it read.

"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," the spokesperson added.