Scarlett Johansson was distracted by men's codpieces during the filming of her new movie

Scarlett Johansson was distracted during the filming of her new movie The Other Boleyn Girl - because she couldn't stop staring at her male co-stars' nether regions.

The Hollywood star said she was amazed at how big the codpieces were under their tight costumes.

"At first I was so distracted, I had never worked on a film that had used codpieces and now in the modern productions I request them," she joked.

She then said she got the role of Anne Boleyn's sister Mary after her co-star Natalie Portman suggested her for the part.

"I originally got the script through Natalie, she had been attached to play Anne and I heard there was a project and was asked if I'd be interested in playing her sister," she said.

"I was a huge fan of Natalie's, I've been a huge fan of hers for a long time and so I jumped at the opportunity. I read the script and it's really rare to find a project where there is two meaty roles for women."

Her co-star Natalie then admitted she has spent so long in England filming she has picked up some of the cockney rhyming slang. "I've got some more slang like 'take a butcher's' and also your 'boat race' means face," she said on morning show GMTV.