A Texas judge has temporarily blocked the state from investigating parents who provide their transgender children with gender-affirming medical treatments, following a hearing in which one state inspector said they were told to pursue parents even when they did not think abuse had occurred.

The temporary halt, issued by a district court judge on Friday, follows a lawsuit brought by the American Civil Liberties Union against the state’s Republican governor, Greg Abbott, who the organization accused of trampling “on the constitutional rights of transgender children, their parents, and professionals who provide vital care to transgender children”.

Judge Amy Clark Meachum held a hearing on Friday as she considered a request to temporarily block Abbot’s order. Randa Mulanax, an employee of the Texas Department of Family and Protective Services (DFPS), was the first witness to testify.

Mulanax said that she has resigned from the department because of concerns about the directive, and said cases involving gender confirming care were being treated differently than others. Mulanax said her agency did not give workers the option to determine a reported case of child abuse involving a transgender child was “priority none” status, meaning it did not merit investigation.

“We had to be investigating these cases,” Mulanax testified, adding that she has handed in her resignation notice because she believes the directive is “unethical”.

Such investigations could remove trans children from families and jail parents who provide them with procedures.

The hearing is part of pushback by LGBTQ+ groups against conservative politicians’ proposals in dozens of US states to criminalize gender-affirming procedures for trans youth in the run up to midterm elections.

Abbott ordered doctors, nurses and teachers to report such care or face criminal penalties.

The ACLU asked Meachum to impose a statewide injunction on investigations by the DFPS into what the civil rights group said was “medically necessary gender-affirming care”.

Meachum last week temporarily blocked an investigation into the parents of a 16-year-old transgender girl, saying it would make them the subject of “an unfounded child abuse investigation”.

Opponents of gender-transitioning procedures say minors are too young to make life-altering decisions about their bodies. Advocates argue that it is crucial care that has been politically weaponized, impacting the mental health of trans youth who suffer a disproportionately high rate of suicide.

More than 60 major US businesses, including Apple and Johnson & Johnson, signed their names to an advertisement that ran in Texas on Friday opposing Abbott’s directive, saying “discrimination is bad for business”.

The DFPS has opened nine child welfare inquiries subject to Abbott’s directive, a spokesman said.

Megan Mooney, a clinical psychologist, said the governor’s directive has caused “outright panic” among mental health professionals and families of transgender youth.

“Parents are terrified that [child protective services] is going to come and question their children, or take them away,” Mooney testified. “Mental health professionals are scared that we’re either violating our standards and professional codes of conduct, or in violation of the law.”