By Mike Collett-White

VENICE (Reuters) - Oscar winner Ang Lee, director of gay cowboy classic "Brokeback Mountain," returns to the theme of forbidden love with a sexually explicit thriller set in the teeming streets of 1940s Shanghai.

"Lust, Caution" is based on a short story by Eileen Chang, and follows a group of revolutionary students who hatch a plot to assassinate a powerful political figure who is collaborating with occupying forces during the Sino-Japanese war.

First-time actress Tang Wei portrays the young woman who agrees to ensnare the sinister figure, played by one of Asia's biggest screen stars Tony Leung.

The movie is in the main competition at the Venice film festival, where Lee won the Golden Lion award with "Brokeback Mountain" in 2005 and went on to garner eight Oscar nominations.

Media attention ahead of the new movie's release this year will focus on the long, acrobatic and sometimes disturbing sex scenes between the main characters, which Lee hinted were real.

When asked in Venice about the authenticity of the sex, he replied: "Did you see the movie? Then why do you ask?"

In a recent interview Lee described his new film as "a scary place," and "like hell." But although lust is used to lure a man into a dangerous trap, love's power also offers a glimmer of hope to characters caught in a world of violence and fear.

"Lust, Caution" marks the Taiwan-born director's return to Chinese-language drama after several English films made in the West. He said his position as someone who works in Asia and Hollywood had helped his career.

"Being in between two worlds really helped me understand both cultures, the Western culture and particularly my own cultural roots," Lee told reporters in Venice, where the film was having its world premiere later on Thursday.

SHORT STORY, LONG FILM

East and West meet in "Lust, Caution," with a character visiting a cinema and watching a 1940s English-language classic and a poster for Alfred Hitchcock's 1941 thriller "Suspicion" appearing on the wall.

Lee, who also made "Crouching Tiger, Hidden Dragon," said he had to expand on Chang's original story, which was only 28 pages long, for the plot of his two-and-a-half hour film.

"The novel had to be just a starting point and not the destination," he said. "I had to get outside the novel, but being faithful to what she wrote, to what she said."

The story partly reflects Chang's real-life story, in that she fell in love with a man who was labeled a traitor for collaborating with the Japanese.

In the United States, the film has been given an NC-17 rating, the Hollywood Reporter said, meaning no one under 17 will be admitted and limiting its box office potential.

Just before the Venice film festival opened on Wednesday, Taiwan protested after "Lust, Caution" was labeled as coming from "Taiwan, China" on Web sites promoting the event.

China has seen self-ruled Taiwan as part of its territory since the island broke away after civil war in 1949, and seeks to lower Taiwan's profile by asking sports and cultural organizations to add "China" to Taiwan entries.

Lee skirted the issue, when asked his opinion.

"If you can find out what's going on, please let me know," he said through an interpreter, referring to the confusion surrounding the description.
© Copyright 2007 Reuters.

Photo:
Director Ang Lee (C) poses with actors (L-R) Tony Leung, Tang Wei, Lee-hom Wang and Joan Chen pose during a photocall session in Venice August 30, 2007. Lee presents his movie, in competition, "Lust, Caution" during the 64th Venice Film Festival. REUTERS/Alessandro Bianchi