LeAnn Rimes -- Flip-Flopping on 'X Factor' Performance

Someone in LeAnn Rimes' camp is LYING ... because the singer is now saying she never gave a statement to TMZ about her controversial performance on "X Factor."

Here's the deal -- after reports surfaced that LeAnn may have been wasted during her performance with 13-year-old Carly Rose Sonenclar, we called Rimes' rep for comment.

The rep gave us a quote that we were told we could put on TMZ.com and attribute to LeAnn Rimes. We were told LeAnn was NOT impaired and if there was any awkwardness it was only because "I was trying to help this 13-year-old girl who was having some trouble with the song."

But moments ago, Rimes posted a message on her Twitter page saying she has NOT given the media a quote -- noting, "It's a shame that gossip and lies are overshadowing the performance of Carly."

She added, "It was an amazing opportunity to share this experience with Carly and I know I'll be watching for her to win tonight."