A CALIFORNIA high school valedictorian was abruptly cut off when she tried to speak about sexual assault during her graduation speech, according to reports.

“I felt like I was worthless,” recent Petaluma High School graduate Lulabel Seitz told CNN about the incident.

According to the New York Post, the 17-year-old dux began her speech on June 2 recalling the students’ first days as freshmen then went on to talk about devastating wildfires, teacher strikes and her own family’s struggles.

But when it seemed like she was about to bring up her own sexual assault, which allegedly happened on school grounds — her mic was cut off.

In a video of the incident, the teen is visibly upset as she yells inaudible words to someone off camera.

Moments later, her peers and people in the crowd started chanting “Let her speak! Let her speak!”

After nearly a minute of silence, she returns to her seat.

Ms Seitz — a member of student government who played trumpet in jazz band and kept a Grade Point Average of over 4.0 — said administrators warned her not to “speak against them” in her speech.

But the night before commencement, as she watched Martin Luther King Jr. speeches, she was inspired to speak up.

“When they cut my mic, I was appalled at them,” Ms Seitz told The Santa Rosa Press Democrat. “I thought this is a public school with freedom of speech.”

Seitz, who is heading to Stanford in the fall decided to post the uncensored version of her speech on YouTube.

That speech contains the line: “Even learning on a campus where some people defend perpetrators of sexual assault and silence their victims, we didn’t let that drag us down.”

The teen said she reported her assault, but that the school did nothing about it.

The Petaluma School District said they couldn’t discuss Ms Seitz’s allegations of sexual assault due to student privacy issues.

“The school just censors people. The school continually censors students,” said Ms Seitz. “It wasn’t an easy thing to do to get up there and say what I said — or tried to say.”

David Stirrat, the principal of the school, said they’d received emailed complaints warning them that Ms Seitz might go off-script.

He maintained that students were welcome to include potentially controversial material in their speeches.

“In Lulabel’s case, her approved speech didn’t include any reference to an assault,” he told the Washington Post.

“We certainly would have considered such an addition, provided no individuals were named or defamed.”

Dave Rose, an assistant superintendent said cutting of Ms Seitz’s mic wasn’t an infringement of her freedom of speech.

“If the school is providing the forum, then the school has the ability to have some control over the message,” he said.

But #MeToo activist and actress Mira Sorvino stood up for the teen, tweeting that Lulabel Seitz should not be silenced.