A 29-year-old woman has been arrested in New Jersey for allegedly posing as a high school student.

The woman, identified by police as Hyejeong Shin, has been charged with using a fake identification document to enrol in New Brunswick High School.

Ms Shin attended the school for four days before staff found out her age.

School officials said police are investigating the matter, and a review of the district's enrolment process will be conducted.

The issue came to light at a local education board meeting on Tuesday, where New Brunswick Public School District Superintendent Aubrey Johnson told attendees that Ms Shin was caught at the school.

"Last week, by filing some false documents, an adult female posing as a student was able to be enrolled in our high school," Mr Johnson said.

He added that she had been in a few classes and spent some time with guidance counsellors, who tried to find out more information about her.

Ms Shin's false age was then uncovered, Mr Johnson said, and the school immediately notified police.

She has since been arrested for providing a false birth certificate "with the intent to enrol as a juvenile high-school student", the New Brunswick Police Department has said.

Students said the woman had texted some of them, asking them to hang out.

One told CBS New York that the girls "never showed up, and she [Ms Shin] started acting weird with them".

New Jersey state law allows students to be enrolled in school even without a guardian or without all the required paperwork, police said.

This is not the first time an adult has been caught posing as a high school student.

A man named Brian MacKinnon posed as a fifth-year student in a high school near Glasgow in 1993 when he was 30 years old. He claimed to be a 17-year-old from Canada.

MacKinnon remained enrolled at the school for a whole year. He was exposed a year later when he was a student at Dundee University's medical school, after a newspaper reported on his real identity.

His story drew worldwide attention and was the subject of a 2022 documentary film.