Used condoms mailed to former classmates in vile attack
Dozens of women who attended a high school in Melbourne's southeast have been targeted with grotesque mail including used condoms.
Police say the offender or offenders used a student-created yearbook from Kilbreda College Mentone's class of 1999, which contained the home addresses of pupils.
The victim count stands at 65, with more than 100 offences as some women have received multiple letters.
The first letter was received on March 20 and the most recent was received on Monday.
Kilbreda College was helping police with their inquiries as officers analysed DNA and handwriting, Bayside sexual offences and child abuse team Detective Senior Sergeant Grant Lewis said.
"We're keeping an open mind in relation to any relationships to the school or the students, or someone who has no association to the school whatsoever," he said on Wednesday.
"It's quite possible this yearbook, which had addresses on it, may have been found by someone who was not associated with the school and may have just thought it ... (was) a joke to start with and now it has become quite serious."
Police urged people who could identify the offender or offenders to come forward and warned they would find them.
Det Sen Sgt Lewis said there were also secondary victims in the case given some of the former students' parents received the letters, rather than their children, who had long moved out of home.
"Some of these people who are receiving this mail and material are quite old so it's quite traumatising for them and upsetting," he said.
Bree, who did not want to provide her surname, was among the victims.
She said students included their names in the yearbook to keep in touch in the pre-social media era.
Her mother opened the letter.
"Her reaction was quite shocked and she was quite upset," Bree said.
"I was very freaked out (and) didn't sleep that night - it was very scary, thinking it was just me.
"The next day, I heard of another girl who had received the same or similar type of letter and then there was another one."
Bree created a Facebook group, leading more of her former classmates to say they too received a letter.
The letter she received was graphic and sexual, she said.
"It was completely disgusting, not something that you would expect in the mail," Bree said.
"Some of our parents are quite elderly and some parents are sick and some of the girls are unwell at the moment. It's just the last thing anybody needed.
"We can't think of anybody who has a grudge against us."
If the letters were a joke to start with, the situation was beyond a joke now, she said.
One of her former classmates had received four letters. Bree said all she and her peers wanted was for the perpetrator or perpetrators to stop.