An actor's positive HIV test has caused two of the US adult film industry's largest studios to postpone filming.
Wicked Pictures and Vivid Entertainment told The Los Angeles Times that production had stopped as a precaution.
The unnamed actor was a member of the Adult Industry Medical Healthcare Foundation.
Clinic spokeswoman Jennifer Miller said efforts were being made to notify other performers who may have had sexual contact with the actor.
This is not the first time the billion dollar industry has faced closures.
In 2004, an HIV outbreak spread panic in the industry and briefly shut down productions at several California studios.
Up to 14 people were believed to have been infected during on-camera sex with a male actor.
Last year, a woman tested positive for HIV immediately after making an adult film.
Officials in Los Angeles have criticised the pornographic film industry for the lack of condom use on porn sets.
According to the Los Angeles County Department of Public Health, workers in the adult film industry are 10 times more likely to be infected with a sexually-transmitted infection than members of the general public.
In August, the Aids Healthcare Foundation (AHF) submitted an official complaint in California against adult entertainment mogul Larry Flynt.
At the time Mr Flynt said he delivered "what the consumer wants".
Federal law requires that all porn actors are tested for HIV 30 days before the start of filming.