Britney Spears might lip-sync while performing through her two-year Las Vegas residency, according to an exclusive report by the New York Daily News.

The pop diva's two year residency at Planet Hollywood starts on Dec. 27. Spears will be performing 90 minute shows (Britney: Piece of Me), featuring 21 of her hit songs, in a 4,600-capacity planetarium-like theater with traditional seating, a dance floor, and private tables. She has confirmed 16 dates as of now, and is scheduled to perform 50 shows in 2014 and 2015. Industry insiders estimate Spears will earn $15 million per year for the shows. The tickets for the show are priced between $59 and $179.

"Britney does not sing. She is being paid a lot of money to lip-sync," a source told NYDaily. "Her fans are none the wiser, but it is disingenuous of her to take their cash and not deliver a proper performance."

In 2009, Spears lip-synced through a concert in Australia, as part of her Circus tour, and fans were very disappointed and demanded refunds.

The NY DailyNews source also revealed that the singer hasn't sung live for a couple of years now.

"If the crowd thinks they are being cheated then there is likely to be an uproar, but then again look at the success of Cirque du Soleil's Michael Jackson shows. The performers in that production don't sing live, and it has been a runaway success," the source added.

"This is a big Vegas-style production show, married with a dance club environment," Kurt Melian, VP of entertainment at Caesars Entertainment told Billboard in a recent interview. "It's 21 of her greatest hits, effectively, and some of the music from her eighth studio album (scheduled for release on Dec. 3). It's a retrospective on some of the most iconic moments of her life, combined with the more contemporary stuff that she's doing today."

In another interview with Extra's Mario Lopez, Spears spoke about her upcoming gig at Planet Hollywood. While discussing the experience they were planning on creating at Planet Hollywood -- with costumes and a "party vibe" -- Spears said she wanted people to feel like they were in the show with her.

Spears relates to Miley Cyrus, "I remember that age"; Says Cyrus is "on fire right now."

Watch Spears' interview with Lopez:

Tags: Britney Spears Las Vegas