VIDEO: Britney Spears "Extremely Upset" Over Lip-Synching Scandal

Britney Spears is "extremely upset" as the biggest lip-synching scandal since Milli Vanilli unfolds around her, according to her Australian promoter.

About 100 fans walked out of her Friday show at Perth's Burswood Dome, angry at what they perceived were overpriced tickets and performances short on substance. Local media panned the Toxic singer, and officials from three Australian states -- Western Australia, Victoria and New South Wales -- were discussing legislation that would force promoters to tell audiences when their concerts involve lip-syncing.

"Britney is aware of all this and she's extremely upset by it," her Australian promoter, Paul Dainty told newspaper The Australian. "She's a human being. I'm embarrassed, with such a big international entourage here with Britney, to be part of the Australian media, when I see that kind of totally inaccurate reporting."

John Mayer, also in Australia on a promotional tour, weighed in on the scandal via his Twitter account.

"If you're shocked that Britney was lip-syncing at her concert and want your money back," Mayer Tweeted, "life may continue to be hard for you."

Brit will take the stage next in Melbourne, Australia on Nov. 11.

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