The abuse and mistreatment of vulnerable adults at a specialist hospital has been uncovered by the BBC's Panorama programme.
Undercover BBC filming shows staff intimidating, mocking and restraining patients with learning disabilities and autism at Whorlton Hall, County Durham.
Experts said the culture was deviant at the privately-run NHS-funded unit with evidence of "psychological torture".
A police investigation has been launched and 16 staff suspended.
The 17-bed hospital is one of scores of such units in England that provide care for just below 2,300 adults with learning disabilities and autism.
Many are detained under the Mental Health Act.
Glynis Murphy, professor of clinical psychology and disability at Kent University's Tizard Centre, said much of what Panorama had found was the "absolute antithesis" of good care.
"It is obviously a very deviant culture."
Cygnet, the firm which runs the unit, said it was "shocked and deeply saddened".
The company only took over the running of the centre at the turn of the year and said it was "co-operating fully" with the police investigation.
All the patients have been transferred to other services and the hospital closed down, Cygnet said.
Swearing and mental torture - what has been uncovered
The BBC reporter, Olivia Davies, worked shifts for two months undercover between December and February.
She filmed a number of shocking scenes where staff can be heard using offensive language to describe patients, while another calls the hospital a "house of mongs".
In another case, a patient is told by her care worker that her family are "poison".
Two male staff members single out a female patient for particular abuse.
Aware that she is scared of men, they tell her, in an effort to keep her quiet, that her room will be inundated with men.
They call this "pressing the man button", something which causes her great distress.
This was described a psychological torture by Prof Murphy.
What about violence?
There was certainly the threat of violence. On one occasion, a male care worker threatens to "deck" a patient, while another patient is told they will be "put through the floor".
Six care workers also told the undercover reporter that they have deliberately hurt patients - including one who describes banging a patient's head against the floor, and another who speaks about flooring a patient with an outstretched arm, something he called "clotheslining".
The reporter did witness a number of incidents of physical restraint, which should only be used to prevent a patient harming themselves or others.
In one episode of restraint, a patient was held on the ground for nearly 10 minutes with one member of staff restraining him, while handing out chewing gum to colleagues.
Prof Andrew McDonnell, an expert in autism at Birmingham City University, who develops training to reduce the use of restraint, said it was a "cruel punishment".
"Restraint should be momentary. It should be short. It should be with as few staff as possible, without an audience."
What about regulation?
Services for people with learning disabilities are regulated by the Care Quality Commission (CQC).
The CQC gave Whorlton Hall a good rating after inspecting it in 2017.
It said that since then, it had warned the hospital about staff training, long hours and excessive use of agency staff.
Dr Paul Lelliott, deputy chief inspector of hospitals at the CQC, told Panorama: "On this occasion it is quite clear that we did not pick up the abuse that was happening at Whorlton Hall.
"All I can do is apologise deeply to the people concerned."
The Department for Health and Social Care said it treated allegations of abuse with the "utmost seriousness", but could not comment any further because of the police investigation.
Not the first scandal
The Panorama findings come eight years after abuse was uncovered at another hospital for people with learning disabilities, Winterbourne View, near Bristol.
After that programme, the then prime minister, David Cameron, promised the mistreatment of patients would never happen again.
Winterbourne View was shut down and the government committed to closing other specialist hospitals too, saying care should be provided in the community.
Bed numbers have been reduced - from 3,400 to below 2,300 since 2012 in England - but that falls short of the government's target to get it down to below 1,700 by March this year.
The official investigation in the Winterbourne View case also made warnings about the excessive use of restraint.
But figures show "restrictive practices" have become more common - the use of seclusion and restraint has nearly doubled in the past two years, according to figures obtained under the Freedom of Information Act by Panorama.
Health Secretary Matt Hancock ordered an investigation into the cases last year and an interim report published by the Care Quality Commission this week described the system as "broken" and said people who ended up in hospital were being failed.
The sector has also come under fire for some of the deaths that have occurred.
The most high-profile case of recent years was Connor Sparrowhawk, who had learning disabilities and epilepsy, and died when he had a seizure alone in a bath at an NHS unit in Oxford in 2013.
Southern Health NHS Foundation Trust admitted breaching health and safety law and was fined £2m for the deaths of Mr Sparrowhawk and another patient, 45-year-old Teresa Colvin, who died in Hampshire in 2012.
The deaths of people with learning disabilities are now routinely monitored.
The latest report, also published this week, found that there were concerns about care provided in more than one in 10 cases.
Jonathan Beebee, of the Royal College of Nursing, said Panorama had shined a light on a "dark corner" of the sector.
He said the scale of what had been found would not be happening everywhere, but he still had concerns about the state of services.
"The sector is plagued by high vacancy rates and a lack of properly trained staff. There will be problems elsewhere."
Watch BBC Panorama: Undercover Abuse Scandal Wednesday 22 May at 9pm on BBC One