A public health department in the Czech Republic has launched criminal investigations against 30 HIV-positive men whom it alleges had unprotected sex in violation of the country’s laws that make it a crime to expose someone else to HIV.

There are no complainants in the case, nor any evidence anyone has contracted HIV from the 30 men under investigation. The sole evidence against the men is that they contracted other sexually transmitted infections (STI) — like gonorrhea or syphilis — after testing HIV-positive, which the health department contends is proof they had condomless sex in violation of the law.

“There’s absolutely no evidence, there are no victims,” said Jakub Tomšej, a lawyer with the Czech AIDS Help Society, which has provided counseling to some of the men under investigation. “We believe the only consequence [of this kind of investigation] is that HIV-positive people who get another STI will simply avoid doctors.”

Edwin Bernard, the U.K.-based head of the HIV Justice Network, said that the collaboration between a public health agency and law enforcement in this new investigation is alarming because it threatens much of the progress that has been made in Europe in reforming HIV policy.