An adult film performer in San Fernando Valley’s lucrative porn industry has tested HIV-positive, prompting at least two well-known adult movie production companies to suspend filming as a precaution.

The HIV infection of an active porn performer is the first known local case in more than a year and immediately strengthened calls by AIDS activists for the state to mandate condom use on porn sets and to increase regulation.

The case was confirmed to The Times on Tuesday by officials at the Adult Industry Medical Healthcare Foundation, known as AIM, a Sherman Oaks clinic that primarily serves porn industry workers.

“We are quarantining and testing all exposed partners to the individual,” said Jennifer Miller, an HIV/STD counselor at the clinic.

Miller declined to disclose the gender of the person who tested positive, what companies he or she worked for, when the person was tested and whether AIM had notified state and county officials.

“We’re doing what we can to notify the individuals involved,” Miller said.

She said AIM officials plan to release more information at the end of the week.

In the meantime, Vivid Entertainment, based in Van Nuys, and Wicked Pictures, based in Canoga Park, both suspended production Tuesday, citing the positive HIV test.

“We did this as a precaution and will continue to monitor the situation,” said Steven Hirsch, Vivid’s founder and co-chairman. “We will wait for all of the facts to emerge before resume production.”

Wicked Pictures officials, who described their productions as “condom-mandatory,” said they halted filming to allow AIM to create a “comprehensive quarantine list.”

Diane Duke, executive director of the Free Speech Coalition, a Canoga Park-based porn trade association, said it was too early Tuesday to draw conclusions.

“What we know is someone tested HIV-positive; we don’t know the circumstances. What we do know is AIM has identified that someone is HIV-positive and is taking care of it,” Duke said.

However, local AIDS activists, who have petitioned the state’s Division of Occupational Safety and Health and unsuccessfully sued the county Department of Public Health to mandate condom use by performers, demanded that Los Angeles public health officials investigate AIM immediately, seizing records if necessary.

“How many more people have to be infected with HIV before Los Angeles County steps in to do its job and protect performers’ and the public’s health?” asked Michael Weinstein, president of AIDS Healthcare Foundation.

Weinstein said county health officials should demand that the clinic disclose which performers were affected and name the production companies involved so that Cal/OSHA can investigate. Otherwise, he said, “AIM and the industry will do everything in its power to prevent us from knowing how many people were affected.”

Los Angeles County health officials said they had received no notification of the new case but noted that requirements allow seven days for reporting. Cal/OSHA officials said AIM had not notified them Tuesday that a performer had tested HIV positive.

“We think that’s a problem,” said Amy Martin, the agency’s chief counsel. “We’re being stymied right now. We believe it’s critically important that we be able to pursue this for the health and safety of the workers.”

When a performer tested HIV positive at AIM last year, Martin said, state officials demanded that AIM disclose the performer’s work history. The performer filed a restraining order in Alameda County Superior Court barring AIM from releasing the information to state officials; the case is pending, Martin said.

Industry officials said that the actress had worked rarely and that no one else in the industry was infected as a result.