The porn industry in Los Angeles came to a screeching halt Saturday, after a vidoe performer tested positive for HIV.

LA officials ordered an immediate shutdown of the multi-billion-dollar adult entertainment industry by Monday, forcing a number porn sets across the San Fernando Valley to close, losing a substantial amount of revenue.

Diane Duke, head of a porn industry trade group, asked for the closure and said the unidentified performer is being retested while first- and second- generation partners are contacted, the Los Angeles Times reports.

The porn industry employs in excess of 12,000 people in California. And in California alone, we pay over $36 million in taxes every year. So it's a very sizable industry, says Bill Lyon, a former lobbyist for the industry.

The Free Speech Coalition, the trade group that reported the incident, was made aware of the test results on Saturday and asked for the immediate shutdown by Monday morning, MSNBC reports.

“Until we know for sure, we’ve asked the industry to have a moratorium on production,” Duke, executive director of the coalition,  told the Times.

In California, adult performers must be tested every 30 days and must show proof of clean tests before they can perform. Los Angeles County health officials and state health regulators were not notified of the tests earlier because they were performed out of state.

Duke told reporters that the unidentified person tested positive at an out-of-state facility that does not appear to have protocols or procedures in place for medical follow-up, including testing of contacts.

The group has yet to release information on the performer's name, age, or gender.

It's unclear exactly what procedure the group is following, but Duke says, retesting and confirmation is under way, as is the process of identifying and testing first- and second- generation partners.

The Los Angeles-based AIDS Healthcare Foundation is seeking to get a measure placed on the city's June 2012 ballot that would require adult film performers to use condoms in order for porn filmmakers to obtain city film permits.

In order to accomplish this, they must submit a petition with at least 41,138 qualifying signatures by Dec. 23 to place the measure on the June ballot.

The Los Angeles Times reports that Michael Weinstein, president of the foundation, said the latest HIV case shows why testing is not an adequate substitute for condoms. Weinstein called on Los Angeles city officials to pull all adult film permits until they can require performers to use condoms.

The question remains how many performers must become infected with HIV and other serous STDs before the industry will clean up its act and government will do the right thing? Weinstein said.

The porn industry was shut down similarly in late 2010, after porn actor Derrick Burts was diagnosed as being HIV-positive, the Brisbane Times reports.