Oscar winner Ang Lee has approached Hong Kong "king of film" Tony Leung about appearing in his upcoming spy thriller, "Lust, Caution," Lee's assistant said Sunday.

"It hasn't been confirmed yet. We have approached him, but we won't finalize all the characters until we choose a female lead," the director's assistant, David Lee, told The Associated Press in a phone interview.

"We haven't decided on a female lead," David Lee said.

Observers are closely watching Ang Lee's casting choices to see if he will produce another female star. Lee's box office hit "Crouching Tiger, Hidden Dragon," helped propel Chinese star Zhang Ziyi to stardom.

David Lee said filming for "Lust, Caution" will begin in the fall in Shanghai and Hong Kong.

"Lust, Caution," based on a novel by Eileen Chang, marks Ang Lee's return to Chinese-language film after several English-language productions including "The Hulk" and most recently, the gay romance "Brokeback Mountain," for which he won best director Oscar this year.

Tony Leung won best actor at Cannes in 2000 for his role in Wong Kar-wai's romance "In the Mood for Love." Leung also appeared in the crime thriller "Infernal Affairs," which has been remade by Martin Scorsese as "The Departed."

Editor: Donald