A primary school pupil was trapped kicking and screaming under a bean bag for up to five minutes while his teacher sat on top.
A professional conduct committee hearing was told that Philip Meredith inappropriately restrained the child on the floor under the bean bag - which was the size of a double bed.
Teaching assistant Ellen Sheldon, who was in the classroom at Ty Sign Primary School in Risca, Wales, at the time, said: "There was a fight between Pupil A and another child.
"Pupil A was put into a restraint by Mr Meredith on to the bean bag. I didn't see how he got from there to under the bean bag.
"I could see his feet kicking and he was shouting 'Get off, get off'. I would estimate he was under the bean bag for four to five minutes."
She added: "I've never had to deal with anything like this... and I never want to deal with it again. It's made me feel ill."
She reported the incident - which allegedly happened on November 17, 2011 - the following month, and Mr Meredith was subsequently suspended. He was later dismissed.
Mr Meredith is now appearing before a General Teaching Council for Wales (GTCW) professional conduct committee, facing seven charges of professional misconduct.
Headteacher Alison Dacey told the hearing that Mr Meredith was appointed in September 2011 to a role which involved teaching some of the more demanding pupils at the 430-pupil school.
She said some of the pupils 'had very challenging behaviour' and she added that 'unruly and violent behaviour' was not uncommon.
But she said from an early stage there were concerns about Mr Meredith's conduct and behaviour, including 'shouting and yelling' at pupils.
The hearing, in Cardiff, continues.