Keira's movie wind

Keira Knightley couldn't stop belching during the filming of 'The Duchess'.

The 23-year-old actress - who stars as Georgiana, the Duchess of Devonshire, in the new movie - admits continuously wearing an array of corseted outfits played havoc with her digestive system.

She said: "Big frocks, big hair, big jewels, tight corsets - all very restrictive. The worst part is after lunch because they really don't help your digestion. My co-star Hayley Atwell and I were there playing these very ladylike characters but we were belching all over the place!"

Keira also said it took her a while to get used to the incredibly tall wigs her character required.

She added: "Georgiana was a massive fashion icon who designed her own clothes, so they are absolutely extraordinary. You had to be stitched in and cut out which is how they would have done it. And the wigs were like bird cages, made out of metal and stuck to your head with hair over the top.

"I couldn't hold my head up and they built me a wooden stand between takes so I could rest the wig on it. As everyone was walking past they would shout, 'Timber!' I was like, 'Thanks for the support, guys!' "