(Cover) - EN Showbiz - Keira Knightley has been tipped to star in the new Alien prequel.

Director Ridley Scott is on the lookout for a confident female lead for the movie, which will reveal what happened to the killer extra-terrestrials before the original 1979 Alien film which starred Sigourney Weaver as Ellen Ripley. Ridley reportedly believes the British actress would be perfect for a role in the film, but is also interested in American star Natalie Portman.

This isn't the first time Ridley has been on the lookout for a strong female lead and that's just what he sees in both Natalie and Keira," a movie insider revealed. "Both would be ideal for the role but with Keira, it would be a departure from what she's known for. It all depends on who looks best covered in alien gloop!"

Keira and Natalie are not the only Hollywood beauties linked to the female lead role.

Earlier this month it was reported Carey Mulligan had met with Ridley to discuss the movie.

Other actresses also linked to the part include Anne Hathaway, Abbie Cornish and Swedish star Noomi Rapace, who starred in the original big screen adaptation of The Girl with the Dragon Tattoo.

The new movie will be shot in 3D and is due to be released in 2011. (C) Cover Media