Model/actress Kelly Brook has revealed the secret of her famous figure for a cheeky new charity film - by pulling socks out of her bra.

The busty British beauty teamed up with the U.K.'s Sport Relief organization to shoot the commercial, in which she is seen writhing seductively in a red evening gown.

A voiceover then announces, "You too could have a pair like Kelly's" before the director yells "cut!" - and Brook is seen pulling several thick socks from her cleavage.
 
Explaining the jokey clip, which will run in the U.K. to promote the upcoming charity drive, the Piranha 3D star says, "My secret's out! Sports Relief (sic) socks are an essential item in my styling kit."