Porn production in Los Angeles was given the green light to resume by an industry trade group after an HIV scare last week halted production.
An adult film performer who tested positive for HIV was retested and the actor does not have the virus, according to Free Speech Coalition.
"The industry will be abundantly cautious as we try to nail down the reasons for what now appears to have been a false positive result on a previous test," said FSC executive director Diane Duke.
But production can now resume, she said.
Earlier this week, AIDS Healthcare Foundation, who is working on a ballot initiative to make condom use madatory in adult films, criticized FSC for not disclosing more information about the incident.
The actor, who was in Florida, had been slated to work on a shoot for Mofos.com, but production was halted last week when the test came back positive for HIV.
On Wednesday, AHF filed complaints with the Florida Department of Health and federal OSHA officials to investigate and ensure performers in the industry are protected from sexually transmitted infections.
Additionally, the group's president, Michael Weinstein, accused FSC of obstructing an investigation in Los Angeles County and demanded the group provide "necessary information to health authorities."
But FSC said there was no investigation.
"It is impossible for FSC to obstruct an investigation that, evidently, does not exist," FSC said in a statement. FSC said it received no contact from Los Angeles County Public Health, out-of-state health officials, or AHF.
Duke declined to release the performer's name, age or gender, citing the person's right to medical privacy. She also declined to say how her group learned of the case.
AIDS Healthcare Foundation remained skeptical of FSC's role in the incident.
"For the sake of that person and all who performed with him, I'm glad to hear they were in fact negative," said Weinstein. "As far as how this case was handled, we're as troubled as we've ever been."
"Testing itself is not a form of prevention," Weinstein said. Performers can have a negative test result but still be positive and pass on HIV depending on when the test was performed, he said.
He also questioned why an industry trade group was heading up the investigation and not local health authorities.
"If this were a food contamination case, we would not allow an industry trade group alone to investigate," he said. "The FDA would be involved."
Production has been shut down since Monday in the San Fernando Valley's multi-billion dollar adult entertainment industry, which includes Hustler and Evil Angel's productions. The case was found at an out-of-state clinic that does not report to California health officials, Duke said.
The porn industry was similarly shuttered in late 2010, after porn actor Derrick Burts was diagnosed as HIV-positive. His case was confirmed, and he has since left the industry to become an advocate for the use of condoms in pornography.
FSC is working on a database to track sexually transmitted disease testing among porn actors, a task formerly handled by the Adult Industry Medical Healthcare Foundation before it closed in December 2010.
Known as AIM, the San Fernando Valley clinic had catered to porn stars since it opened in 1998. It was forced to close because of inadequate licensing.