The 26-year-old actress revealed the accident happened when she was filming a stunt for action blockbuster 'G.I. Joe'.

She revealed: "I had every intention of working out but it just didn't happen - I've never been to the gym.

"I got burnt boobs, I ran the wrong way under an explosion. It was my own fault, I'm clumsy, there's a little scar."

Sienna - who stripped off in 'Factory Girl' and the forthcoming 'Hippie Hippie Shake' - also admitted she finds nude scenes uncomfortable because of "perverts" on set.

She added: "The damage is done, everything's been seen! It's a little bit awkward at the time. There's the odd perve in the corner."

The 'Edge of Love' star also boasted to UK talk show host Jonathan Ross about her drinking ability, but denied she is a party girl.

She said: "Not as much as is made out. I can handle it. I can drink most grown men under the table."

Sienna's new movie, 'The Edge of Love', is out in cinemas now.

(C) BANG Media International
Photo: WireImage.com

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