The 27-year-old singer was performing a duet with show host Hugh Jackman at LA’s Kodak Theatre, where they paid tribute to musicals, working their way through a medley, including hits from Chicago and Moulin Rouge.

But those watching the performance were sceptical as to whether Beyonce, a.k.a. Sasha Fierce, sang live or had some technical help.

“Was Beyonce lip-synching?” the Metro quoted one fan as asking.

Another disappointed fan claimed that she mimed, and did not performed live like Jackman.

“Beyonce mimed. Egregiously. I don’t understand…Hugh Jackman sang live, why couldn”t she?” the fan wrote in a post.