A “superhead” of an ultra-selective London grammar school left sixth-formers feeling suicidal and staff feeling bullied with a “constant emphasis” on perfect exam grades, a report has found.

Aydin Önaç’s focus on his pupils at St Olave’ Grammar School in Orpington achieving A* grades and Oxbridge admissions left one student feeling he “might as well kill himself” after his offer of a place in Year 13 was withdrawn when he missed the three-Bs target in Year 12 exams.

A report by Bromley Borough Council has concluded that 66-year-old Mr Önaç, who resigned from his £200,000-a-year post last year, was wrong to enforce the policy, which it says has left some children “medically diagnosed at risk of suicide”.

Pupils received the news in a school office with no adult present and emerged “deeply distressed”. One staff member overheard a student say he was so fearful of telling his parents he had to leave “he might as well kill himself”, and another student saying “they just want to be rid of me, they just want me gone.”