HONG KONG (AFP) – A Hong Kong movie billed as the world's first 3D porn film has broken the city's first-day box office record previously set by Hollywood blockbuster Avatar.

"3-D Sex and Zen: Extreme Ecstasy" took in HK$2.8 million ($360,000) on its first day last week, outpacing director James Cameron's science fiction epic which drew HK$2.6 million, the porn movie's publicist told AFP Thursday.

The film has taken more than HK$15 million since its release, she added.

Curious movie-goers from all walks of life -- office workers, retirees and students -- stood in long queues outside Hong Kong cinemas on the film's first day last week, eager to catch an eyeful of the steamy 3D action.

Loosely based on a piece of classical Chinese erotic literature, the $3.2-million Cantonese-language movie features orgies, swinging and some very graphic sex scenes.

Set in the Ming dynasty, the film chronicles the story of a young man who, after being introduced to the erotic world of an aristocrat, realises his ex-wife is the love of his life.

The film stars Japanese adult actresses Yukiko Suo and Saori Hara.