They say sex sells, and it now seems that sex in stereoscope is at least twice as marketable. A Chinese film billed as the world's first 3D porn movie may get a sequel after opening to enthusiastic audiences in Hong Kong.

Sex and Zen 3D: Extreme Ecstasy packed cinemas across Hong Kong yesterday as curious filmgoers flocked to see the highly hyped movie for themselves. The film, set at the raunchy court of Ming-dynasty ancient China, is a sequel to an earlier Chinese movie, 1991's Sex and Zen, which remains Hong Kong's highest-grossing adult film.

"It depends on the box office of 3D Sex and Zen, but we're hoping the sequel will start production as soon as the end of 2011 with an all-new cast," producer Stephen Shiu Jr told the Hollywood Reporter. He said Imax had rejected the film for screening in its Hong Kong cinemas "because of the subject matter and content", but added: "For our premiere in Taiwan, we will show the film in an Imax 3D theatre using their 3D screening equipment."

More than 70% of tickets for Sex and Zen 3D have already been sold in advance of Hong Kong screenings, some of which are completely sold out, according to reports. The film has also attracted tourists from mainland China, where the movie is unlikely to screen without severe cuts due to strict censorship laws.

Justin Lai, 32, said she was curious to see what 3D porn looked like on the big screen. "I'm not normally much of a moviegoer, but this one is just too good to miss," she told AFP as she waited to see the film at a cinema in the busy Causeway Bay entertainment district.

The 113-minute, $2m Cantonese-language film has been handed a category III rating by Hong Kong censors, which means it cannot be seen by under-18s. It stars two of Japan's best-known adult actors, Yukiko Suo and Saori Hara. An ornate fantasy with high production values, the film is ostensibly based on the classic Chinese erotic text The Carnal Prayer Mat and follows a young man as he befriends a duke and enters a world of royal romps.

Its success suggests similar 3D fare could be on the way as the industry attempts to find new ways to make money in an era of free internet porn. Italian director Tinto Brass is reportedly planning a 3D version of his salacious 1979 effort Caligula, while Hustler magazine wants to shoot a 3D porn spoof of James Cameron's Avatar.

Sex and Zen 3D: Extreme Ecstasy opens in Taiwan today. Its producer says distributors across Asia, as well as in Europe and the US, are keen to screen it in cinemas.