Los Angeles, Apr 29 (IANS): Singing live on the camera in the 2012 musical drama "Les Miserables" was her biggest challenge, says American actress-model Amanda Seyfried, who was also a part of 2008 musical romantic-comedy "Mamma Mia!".

Though the cast members of the latter used to sing live instead of pre-recording their vocals, Seyfried, who played Cosette in the musical, feared she may not have the stamina to carry it off.

"(My biggest challenge was) singing live on camera," femalefirst.co.uk quoted the 27-year-old as saying. "It was such a different style from the songs I did in 'Mamma Mia!' and a lot of people, including me, were scared I wouldn't have the stamina for it. But I worked really hard with my voice coach."

The actress also revealed that her biggest regret was to quit opera-singing as a teenager.

"(My biggest regret is) quitting opera singing training when I was 17 - that had been my passion before acting took over and I wish I had stuck with it," she said.