Angelina Jolie reportedly had a "mommy tuck" following the birth of her twins.

The actress - who welcomed Knox Leon and Vivienne Marcheline, her fifth and sixth children with partner Brad Pitt, into the world in July - stunned fans with her svelte figure at the premiere of her new movie "The Changeling," after staying out of the spotlight for three months.

However, it has been claimed Angelina went under the surgeon's knife to get rid of her post-pregnancy pounds, and didn't lose the weight through breastfeeding as she recently claimed.

A source close to the 33-year-old actress told America's Star magazine: "She doesn't like to talk about it or admit it, but Angie told some friends that she had a 'mommy tuck.' She likes the way that sounds better than 'tummy tuck.'"

Angelina - who also has three adopted children and a two-year-old daughter with Brad - recently revealed she is enjoying the challenge of raising six kids.

She said: "It's so much fun but it's very hard work. The kids are forming beautiful friendships. They're teammates and they're very loving to the babies. "

The twins are just the sweetest little things. They lay next to each other. They're starting to smile a lot. Knox looks like Brad and Vivienne looks more like me. They are developing interesting personalities. Knox seems more relaxed and Vivienne is more loud."