A transgender, born a woman but who identifies herself as a man, has triggered a controversy at a high school in San Diego, California after she started using the boys' locker room.

Parents packed the Poway Poway Unified School District board meeting Tuesday as they asked about student rights, according to the San Diego Tribune.

Parent Holly Franz said she found out from her son three weeks ago that the transgender student was using the locker room at Rancho Bernardo High School to change.

"My son came home from school and told me there was a girl using the boys' locker room," she said before the meeting. "This is someone he's known for years and has always been a girl. My son was very upset by this, and I called the principal."

A California law that took effect in January 2014 allows transgender students to use bathrooms and locker rooms of their own choice, the report said.

Franz said boys in her son's class were uncomfortable with the idea of a girl using their locker room with them when they change clothes.

"When I think about all the permission slips that I've had to sign over the years for my kids to watch a PG movie or a PG-13 movie in the school classroom, and yet they could be facing a potentially R-rated situation right in front of them in the locker room, and I don't get to be notified, that's just not okay," she said, according to Christian News Network.

Franz said she received death threats because of her stance on the matter.

Her son, Jonathan, testified that he felt uncomfortable with seeing the transgender in the boys' locker room.

"I walked in and saw a student who I've known as a girl for years but now claims she's a boy. It makes me feel uncomfortable to change around a female body," she said.

One male student defended the transgender's right to use the facility.

"The very fact that we are singling out this boy is already deplorable. To say that this student should have to give up his identity because of the discomfort of others is blatantly absurd because I, for one, am uncomfortable with intolerance on our campus," he said.

An online petition on Change.org in support of the transgender student has garnered more than 1,400 signatures.

This petition aims "to influence the district to NOT allow any action to be made including: notifying parents about transgender students using facilities, or force transgender students to use separate facilities."

The board did not decide on the matter and left judgment to Poway Unified School District Superintendent John Collins.

"Over the past two years, we have worked to ensure every student's right to privacy, as well as every student's right to feel safe, valued and included on our campuses," Collins wrote.