Staff at Brighton Secondary School have been forced to change their computer passwords after a group of students gained access.
On Friday, School Principal Olivia O'Neill alerted parents that staff log-ins had been used to view an unknown number of personal and family profiles.
"On Friday 21 September I became aware that a small number of students had illegally obtained and used staff log-in details to gain unauthorised access to our school's computer systems" O'Neill wrote.
The school's computer system was immediately re-secured when the breach was detected.
"The Department's IT specialists have been informed and they are in the process of examining recent log-ins to identify and remedy any suspicious activity".
It's unknown how many files were accessed.
No other school is believed to have been compromised.
Because of the nature of the crime, Police have been informed and are investigating.