Alfie beauty Sienna Miller found her corset so uncomfortable while shooting new movie CASANOVA, she tried to burn it.

The 24-year-old actress stars alongside Heath Ledger in the 18th-century period piece, and she admits that her costume left her in a lot of pain.

She says, "My enthusiasm for the corset lasted for about a half hour because it really hurts.

"I was trying to squeeze down sandwiches that would get stuck. And you can't lay down because you've got a bustle (that sticks)out to there. Heath called me 'Big Bum' for four-and-a-half months.

"I was caught trying to steal it in the middle of the night to torch it."