Following Mariah Carey's live performance at the American Idol finale on May 16, fans took to Twitter accusing the multiple Grammy winner of lip-syncing.

"Watching Carey lip sync is the most painful thing in the entire world," according to a Twitter user named lauren mahaffy.

Another commenter named King Tml wrote: "@MariahCarey Great job 'live' singing on American idol finale!! I can lipsync better than you!!AMATEUR :p"

Added another going by the handle @JadenStyles: "Mariah Carey, if you are going to lip sync on American Idol, at least attempt to make it look real. Or don't perform on behalf of America."

A source confirmed the accusations to Examiner, saying Carey "was singing along to pre-recorded tracks, but it was clear at times she wasn't singing the real high notes. The audience was embarrassed for her."

However, a rep for the singer said Carey "ABSOLUTELY DID NOT" lip sync a medley of her hits on the AI finale. The rep confirmed that the artist - who is also a judge on the show - did in fact sing to a prerecorded track during the episode, but clarified that she "performed with a 40-person choir" and "SANG LIVE."

"No LIP-SYNCING whatsoever! She did 3 takes and thrilled the crowd with singing little songs in between that we're NOT part of her medley," the publicist added.

Many big-named artists sing to a prerecorded track, making it a common practice in the music business. Beyonce did so at the presidential inauguration in January and Will.i.am did the same recently at the 2013 Billboard Music Awards.

Watch the video below to see Carey perform a medley of her hits at the AI finale. She sang Vision of Love, Make It Happen, My All and Hero. Candice Glover was named the season 12 winner of the singing competition. 

Tags: Mariah Carey American Idol