Two male porn performers have tested positive for HIV, and officials say it is likely that one of them infected the other during an unprotected sex scene filmed in Nevada, according to The Associated Press.

Unlike Los Angeles County, which passed a law in 2012 requiring adult film stars to use condoms, Nevada has less stringent rules.

According to the California Department of Public Health, one of the actors at the Nevada shoots had tested negative for HIV but showed symptoms of acute infection during a second shoot.

A statement by the Free Speech Coalition, a trade association for the adult industry, noted the Nevada incident happened in September and is not a “current threat” as stated by California’s health department. It stressed that the Nevada shoot failed to comply with industry standards because although it tested performers for HIV, it did not use tests that can detect earlier infections.

The adult film industry has declared several production moratoriums in recent years related to HIV, but most of those infections are believed to have taken place during the actors’ private lives. The last confirmed on-set HIV infection was in 2004. The current industry standard is for actors to be tested every 14 days.