Bouncers and former military personnel are being hired as 'cover supervisors' by schools in Britain to help control unruly students.
They are being employed as teaching assistants to cover permanent staff when they are off sick, it was claimed.
The National Union of Teachers said schools were turning to people with no teaching experience just because they were "stern and loud".
"The idea is more about crowd control... than education. If you're stern and loud, that's all that's necessary," the Independent quoted Andrew Baisley, a maths teacher from Camden, north London, as saying.
"I have nothing against a bouncer wanting to become a teacher and training for the job, but if you want to be a teacher you need training to work with children," he added.
In one case, a state secondary school in the Midlands approached an agency, which employed bouncers to take two doormen on to their staff.
They were given full-time jobs as 'cover supervisors' - standing in for teachers who are sick, on maternity leave or on courses.
Baisley said neither bouncer had been offered any training before taking on their 'teaching' jobs.
One has since left after a disciplinary offence against a member of staff. Both bouncers were subjected to criminal records checks.
A spokesman for the Department for Children, Schools and Families said: "Heads should ensure that people they employ have the relevant experience and training. Our guidance is that cover supervision should only be used as a short-term solution."