Makers of the new Pirates of the Caribbean film have banned budding actresses with artificial enhancements to apply for a role in the hit series.

Only those ladies who were naturally endowed were to be selected for the movie's fourth chapter, Pirates of the Caribbean: On Stranger Tides, which is due to be released in May 2011.

In a request to casting directors circulated around Los Angeles, the directors said they were looking for "beautiful female fit models. Must be 5ft 7in-5ft 8in, size 4 or 6, no bigger or smaller. Age 18-25. Must have a lean dancer body. Must have real breasts. Do not submit if you have implants," Times Online reported.

The filmmakers further warned about a "show and tell" day with costume designers to detect false breasts.

Knightley, 24, who was 18 when she shot the first Pirates movie, revealed her experience, saying: "I am not that well endowed so they literally painted in my cleavage. It took about 45 minutes every day for make-up artists to add shade and volume and it looked fantastic until it got too hot shooting. Then the make-up would start smearing and the lines running away." (ANI)