A US mother has been arrested after Michigan authorities say she anonymously cyberbullied her teenage daughter and her boyfriend for more than a year, reports say.

The 42-year-old Mt Pleasant mother faces multiple charges, including stalking, following the series of harassing messages that began in early 2021, according to WKRC.

"We had tens of thousands of text messages, whether they were messages that were just for her daughter or some of her daughter's friends," Isabella County Prosecuting Attorney David Barberi told KTRK.

"And, you know, the digital footprint was just insane."

The teenager told her parents she was receiving harassing messages in texts and on social media for months, and her mother contacted police to purportedly find out who was harassing her daughter, according to WWTV.

Police determined the mother was using special software to hide her location, allowing her to use different phone numbers to catfish her daughter, WKRC reported.

When the harassment began, the mom was a basketball coach at her daughter's high school. William Chilman, the superintendent of Beal City Public Schools, told Good Morning America the district was not expecting a parent to be responsible for the messages.

"When they informed us later in the spring that they were suspecting that it possibly was her, it was a shock to all of us, I think everybody involved," Chilman said.

Barberi said the mother admitted to sending the texts, according to The Morning Sun, but it remains unclear why she sent the harassing communication.

Before her admission, she tried framing another minor, The Morning Sun reported.

"Someone else coined the term, it wasn't myself, but they called it a version of 'cyber munchausen syndrome'," Barberi told WWTV.

"In a sense that this seems to be the type of behaviour where you're making somebody feel bad or need you in their life because of this behaviour."

The mother was reportedly released from jail on a US$5,000 bond.