At a concert in the Mexican capital last weekend, there were clips taken of the singer which led to speculations that she was not really singing.
Duff’s spokesperson denied these allegations and told People, "She was not lip-synching. It was faulty equipment. There was no sound coming out, but she was singing."
The star’s microphone was not working for a few seconds which explains why Duff’s voice could not be heard while the music continued playing.
Her spokesperson added that this is not at all an incident such as the one produced by Ashlee Simpson on Saturday Night Live in 2004, when the star admitted to lip-synching.