The BBC is reporting that it now understands an investigation into allegations of physical abuse of vulnerable boys at a residential school in Devon centres on restraint methods used by staff.
Chelfham Mill School, near Barnstaple, which is privately run, has been closed by the regulator Ofsted.
A former student told the BBC he was forced to wear pyjamas all day when he broke the rules.
The school said it was committed to supporting the investigation.
It added it expected to stay shut for at least six weeks, but detectives have told the BBC their investigation is likely to take several months.
BBC South West’s Home Affairs correspondent, Simon Hall, said: “Detectives say they’re looking at recent claims of excessive restraint, along with some dating back several years.
“Officers told me a number of allegations had been made by pupils against a small number of members of staff.”
One former student told the BBC that boys were “often restrained, and with some force”, but they did not complain as they expected it.
He said “the humiliations were much worse” than being restrained and “pupils sometimes had to wear pyjamas all day, walking around school and at lessons”, as one punishment if they misbehaved.
Another former pupil said: “It was like a prison for children. I can assure you the abuse is real. It happened to me and I still suffer from it now…”
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