Ivanhoe Grammar School has unwittingly revealed the identities of about 1000 former students in an email blunder that could have identified victims of sexual abuse.

The private school emailed the alumni to offer counselling to anyone who may have been sexually abused by one of their teachers, who is facing multiple criminal charges.

Ivanhoe Grammar Credit:Stephen McKenzie

But instead of listing the email address in the "BCC" section - which would ensure the identities remained undisclosed - they were added in the "CC" section, which meant everyone who was sent the email could see everyone else's name and email address.

The school declined to comment.