Supermarket giant Tesco has said it is investigating after footage emerged which allegedly shows staff restraining a vulnerable shoplifter who has schizophrenia and other mental health issues.
The video appears to show two men using force to pin the man to the floor in a room at Tesco's store in Savile Street, Sheffield, last month.
The man told ITV Calendar News he had his face smashed into a wall, had a cup of water thrown at him and was on the floor for 10 minutes during the ordeal.
He told the programme: "But when the man came in and smashed my face into the wall, I was petrified and thought he was going to kill me.
"Then when the two of them dragged me on to the floor, I thought they would pummel me, beat me up."
He said: " What they did was wrong. They aren't the police or the law - they are supermarket workers."
The programme, which did not identify the man, said it had been given the CCTV footage by a whistle-blower at the supermarket.
It said the shoplifter was given a conditional discharge after admitting stealing shampoo and conditioner and for causing criminal damage to a table when he appeared before Sheffield Magistrates' Court earlier this week.
The man's mother said: " I am appalled that these men can do what they did to a vulnerable person."
A Tesco spokesman said: "These are extremely serious allegations. We are conducting our own investigation and will of course fully support the police with theirs."