Christina Aguilera's departure from The Voice US has reportedly come as "no surprise" to those who worked around her.

The singer and Cee-Lo Green announced their exit from the hit TV talent show after this series, with Shakira and Usher takings their places on the panel.

Christina revealed that she was leaving the show to concentrate on her music career, but insiders say this may have not been the only reason.

"Christina could sometimes be high-maintenance on the show. The fact that she's now leaving The Voice has come as no surprise to those who worked around her," a source told British magazine Heat.

"Reports of Christina's behaviour - including her making out with her boyfriend in her dressing room - hadn't gone unnoticed."

Christina discussed her departure from The Voice US earlier this year.

"As I have expressed since day one, I am a singer and performer first and I am so excited to get back to that love," she gushed.