A Victorian high school student gained access to the medical information of fellow students from a school IT system after stealing a teacher's password.
The Camberwell High School student is under police investigation for allegedly trawling through databases on the school's IT system.
The state education department allege the student used a staff password to gain access and would have been able to see contact details, medical information and Medicare card numbers.
Some of the information was then shared with a small group of students.
"We wouldn't describe this as hacking," education department regional services deputy secretary Bruce Armstrong told 3AW.
"Students have gained access by staff passwords.
"It's very serious and sensitive information and we can understand why people are distressed."
The department says the breach isn't linked to a recent IT breach at Blackburn High School.
In that incident, phishing emails purporting to be from the school's principal were sent to parents asking for credit card details.
The education department is making sure the Camberwell incident can't happen anywhere else, a spokesman says in a statement.
