A secondary school leaked the names of pupils with autistic spectrum disorder and other health conditions during an assembly slideshow.
An investigation has been launched following the blunder at Brechin High School in Angus on Monday.
The UK Information Commissioner has been told and the school’s headteacher is contacting parents of pupils identified in “error”.
Professional support has also been put in place for the children affected.
Brechin High School head teacher Archie Bathgate said: “We realise it was wrong and it is very inappropriate that it’s happened.
“As soon as we became aware of it we notified the local authority and we also notified the UK Information Commissioner.
“I believe things are already under way in terms of an investigation into this.
“Our main concern in this are the young people involved.
“A lot of their personal information was shared, things that they were keeping just to themselves, and has been shared publicly, so we’ve tried our best to respond to that.
“Yesterday I phoned and got almost all of the parents and apologised on behalf of the school and today I’ve been trying to follow up with as many of the young people as I can.
“I’ve got my staff checking in with all of the young people that are in and I’ve also met with parents and young people today myself.
“We realise it was wrong and it is very inappropriate that it’s happened.”Archie Bathgate, Brechin High School head teacher
“[We are] really just trying to reassure them that it is a mistake, that we are putting actions in place to make sure it doesn’t happen again.”
The local authority branded the incident as “unacceptable” and said it “should not have happened under any circumstances”.
An Angus Council spokesman said: “We can confirm that personal details were inappropriately shared to a pupil-based audience at one of our secondary schools on Monday.
“This is unacceptable and should not have happened under any circumstances.
“We apologise for the obvious upset and concern this has caused, particularly to those young people whose details were shown.
“Enquiries are under way to establish the full circumstances of this isolated incident and whether any individual learning requires to be provided to ensure there can be no repeat of such an error.
“The UK Information Commissioner has also been advised.
“The headteacher has contacted and continues to reach out to parents of the young people whose information was wrongly shared.
“Professional support is in place and being provided to and available for any young people affected.”