BEIJING (Reuters) - China is cracking down on "vulgar" entertainment and asked all video and audio producers to check their inventory for risque material with threats of fines and other punishment for those who do not weed it out.

The new order from China's top publishing officials comes just days after Beijing slapped restrictions on internet sites that allow users to upload video or audio, and handed a two-year film-making ban to the team behind steamy film "Lost in Beijing".

The regulations and sanctions suggest Beijing is keen to step up its control of the cultural arena ahead of the Summer Olympic Games it will host in August, which are widely seen as a coming out party for the rising political and economic power.

Producers of audiovisual content have around three weeks to look through their inventory for "vulgar" items and report to authorities, the General Administration of Press and Publications said in a statement posted on the central government Web site.

This will be followed by around two weeks of official checks, then over a month to hand out warnings and punishments to any violators who did not voluntarily confess, said the statement which was dated December 25 but only published on Saturday.

"Some audio-video products, in the name of "sexual health" and "sex education", but without any scientific content, use colorful pictures or text containing seductive words to lure customers," the report said.

Others publish titillating pictures to attract customers but under the apparently innocuous title "human body art", it added.

But officials and artists do not always agree on where the line should be drawn between pornography and art, a row that flared up when an unapproved version of the film "Lost in Beijing" screened at the Berlin Film Festival.

The movie features explicit sex, as well as showing who the winners and losers as China's booming economy widens the wealth gap. Censors asked director Li Yu to cut 15 minutes dealing with rape and class conflict.

WEBSITE CRACKDOWN

The government also cited concerns about public morality among the reasons for launching new controls on Web sites that allow users to share videos or offer video programming.

U.S.-based YouTube and Chinese competitors have become popular with Web surfers in the world's most populous nation. Much-watched clips in recent months have included the wife of a top sports anchor publicly denouncing her husband's infidelity.

But Beijing is likely equally concerned about postings by activists and disgruntled citizens of everything from footage of protests to a video diary of life under house arrest.

The new guidelines come into force at the end of the month and require these sites to have permits, for which only state-owned or state-controlled companies will be able to apply.

Successful companies will be expected to police their sites to keep out content deemed socially or sexually improper.

"The Web sites ... should support (an ethic of) serving the people, serve socialism, and remain committed to proper guidance," the rules said.

They were condemned as an "unprecedented act of censorship" by freedom watchdog Reporters Without Borders.

"Under the pretext of developing China's media industry, the authorities are stepping up control of online content, especially in the run-up to the Beijing Olympics," the group said.

"Preventing people from sharing video and audio files denies them the ability to show and describe their lives."