Britney Spears has been described by sources as a corporate "puppet", who is more interested in smoking cigarettes and watching television than making music.
A former friend of Spears, who claimed to witness the recording of her latest album Femme Fatale, argued that the 'Till The World Ends' singer only seemed comfortable singing other people's lyrics and participating in recycled dance routines.
The insider told The Mirror: "She was basically like a puppet who would be told do this, do that, and then be asked to sit down again. It was sad.
"From what I saw, she does nothing more than lend her name and celebrity to the production. That's all she seems either willing or able to contribute... Britney's job is basically to follow other people's instructions.
"When Britney gets home, she does not appear to have much interest in music. The whole time I was with her, she would spend most of her free time doing nothing but watching TV and smoking cigarettes."
However, another source close to Spears argued: "You can't get away from the fact that Britney has been in this game a long time. It's little wonder if she's getting tired of the industry.
"You also have to remember that she is still vulnerable emotionally and it's a miracle she's still up there on stage delivering the goods."
They added: "She may almost act like a dead-eyed robot sometimes and seem managed to within an inch of her life by an army of managers and sycophants. But at the end of the day, she is the biggest star of the last decade, even more so than Madonna and GaGa. And she keeps on going."
Spears is due to embark upon a "post-apocalyptic" 26-date US tour this summer.