WASHINGTON — The Education Department said Wednesday that it is investigating whether a Georgia school district’s policy allowing transgender students to use the bathroom of their choice created a “hostile environment” for a 5-year-old girl who said she was sexually assaulted in a school bathroom.

The complaint, filed on behalf of the parent of the girl, has the potential to upend a heated national debate on transgender students and their access to education bathrooms and locker rooms. The Obama administration sided with transgender students in their choice of school bathrooms, but the Trump administration scrapped that policy and said it was a local decision for schools and states.

Transgender students and their parents say that denying them access to the bathroom of their choice amounts to discrimination. But in this case, conservative activists argue the opposite: Allowing those students to use the restrooms according to their gender identity may discriminate against their classmates.

The agency’s Office for Civil Rights said in response to the complaint that the school’s bathroom policy was one aspect of the investigation. Investigators would also look at the school district’s response to the report of the attack, which the complaint alleged was by “a male student who identified as gender fluid.”

The complaint was filed by the conservative group Alliance Defending Freedom on behalf of a parent at Oakhurst Elementary School in Decatur, Georgia. She charges that last November the transgender boy pushed her daughter against a wall “and forcibly touched her genitals despite her protests, causing her both pain and fear.”

Education Department spokesman Nathan Bailey confirmed in an e-mail that the agency is investigating the complaint.

“The investigation focuses on the school’s response to a report of sexual assault and the examination of any and all factors that may have contributed to a hostile environment,” Bailey said.

The Decatur school district said in a statement that “it is committed to supporting all students.”

“We are aware of the unfounded allegations made by the Alliance Defending Freedom,” the district said. “We fully disagree with their characterization of the situation and are addressing it with the Office of Civil Rights.”

FOLLOW NBC OUT ON TWITTER, FACEBOOK AND INSTAGRAM