Sienna Miller burnt her cleavage while filming her new movie.

The actress – who plays femme fatal The Baroness in "G.I. Joe: The Rise of Cobra" – suffered the embarrassing incident after getting too near to a controlled explosion.

She said: "Luckily it wasn't my breasts, it was the bit in-between. It got a bit burnt when an explosion got a bit close."

The blonde beauty also revealed she hated wearing her character's black leather catsuit. She said: "I won't be wearing one again."

"Squeezing myself into that with the aid of talcum powder every day for five months was more than enough. I could barely move in it anyway."

Although Sienna is proud of the movie, she admits her acting abilities weren't really put to the test. She added: "You know, 'G.I. Joe,' it's not going to be the best acting work we've ever done."

Sienna recently admitted she found it hard learning to throw a punch convincingly.

She said: "The guys I'm fighting are all really tall - and I'm not. I have to kick a lot of them in the head, so just learning to kick very high was a challenge. Learning fights and looking like you're a good fighter is hard."