Wellington Girls' College has apologised to its students and staff after a Year 13 pupil was sent home for wearing a tank top.
On Friday, Lauren Hardie, 17, was asked to leave the school and change her clothes after her top was deemed to be inappropriate by a staff member.
She was also told by a senior staffer that the supposedly skimpy choice of clothing would divert the attention of male teachers.
Lauren, who wore the shirt with high-waisted jeans, said there was no reason for the outfit to be considered provocative.
Speaking to Stuff, fellow Year 13 student Evie Tucker, 17, said the school's 'smart casual' dress code was outdated and encouraged body-shaming among young women.
"Being told your shoulders are not appropriate at school makes you feel sexualised," Evie said.
"Dress-coding... gives young women, especially in this case, the idea that for the rest of their lives what they're wearing is going to control how they're viewed in society, especially by people of authority."
The students have also suggested it was unclear what was considered to be too revealing under the dress code restrictions.
Following the incident on Friday, principal Julia Davidson emailed Year 13 students with a reminder of the dress code, saying the restrictions are also maintained out of sensitivity to other cultures.
"We have a wide range of ethnicities and ages in the school and, so that no-one is offended by you, please be mindful of slogans, not showing too much skin, basically nothing you can see up, down or through, and nothing that could hurt anyone physically," the email said, as reported by Stuff.
The email also pointed out that some students had failed to adhere to the dress code by "showing too much skin".
The school's stance prompted outrage from students - many of whom had become aware of Lauren's treatment on Friday - with a number protesting against the dress code.
On Sunday afternoon, the principal admitted the school had made a mistake in another email issued to the year group. Davidson said the staff had acted "too hastily".
"We hope we'll have the chance to apologise personally to the affected students tomorrow," the email said, as obtained by the outlet. Lauren and other affected students were also apologised to in-person.
The email also apologised for the reference to male staff being distracted by clothing, a comment that implied the young girls were sexualised by their teachers.
"We also want to apologise about any reference that was made regarding our male staff. This was inaccurate and has put them in a really uncomfortable position - something we would never want to do."
The school is now planning to work with a student-led committee to develop a new-and-improved dress code that both pupils and staff are satisfied with.