The California Department of Public Health has issued an HIV alert following a positive diagnosis for the virus in an adult film star.

The actor, who has not been identified, tested positive for the AIDS-causing virus after showing symptoms while shooting two out-of-state films in which he engaged in unprotected sex with several male actors. The actor and the production company believed him to be HIV-negative prior to filming. The alert was issued on Monday, according to the Daily Mail.

"During the second film shoot, he had symptoms of a viral infection," said the department in the alert. "The actor went to a clinic and had another blood test that showed he had recently become infected with HIV."

Another actor from the second shoot has also been tested positive, with officials believing that the first actor may have infected the second one. Officials declined to release the dates in which both films were shot, though they believe that one of the films took place in Nevada.

A trade group in California that represents the adult film industry refused to comment on the matter, according to the Daily Mail.

The porn industry in California recently came under fire after losing an appeal to strike down an ordinance in Los Angeles County, requiring all adult film actors to wear condoms during shoots. The industry criticized the proposal, saying that such a tactic would ruin the “fantasy element” behind pornographic films and would worry viewers because of its references to pregnancy and sexually transmitted diseases.

The ordinance, issued in 2012, has caused a drop in adult filmmakers in the county, with more moving out and a huge decrease in the number applying for permits there from 485 in 2012 to 40 in 2013.

"It's happened before, it's happened now, and it will happen in the future," said Michael Weinstein, the president of a Los Angeles-based AIDS Healthcare Foundation, according to the Daily Mail. "The big lie the industry has been saying all these years, there are no on-set transmissions, has been proven to be untrue."

Officials at this time have declined to release the name of the actor or the film company due to privacy standards.

The California Department of Public Health did not return an email for comment to Medical Daily.