A hospital in Guatemala has been described as the most dangerous mental health institution in the world.
An undercover investigation by the BBC shows heavily sedated, motionless bodies lying in a barren courtyard in burning sun, patients with shaved heads and others walking around naked.
The footage shows patients’ dirty skin covered in their own faeces and more in rags sitting on concrete floors, plastic chairs or on broken, rusting metal beds in the dark, sparse hospital.
The programme also reveals how former patients claim they were raped in the institution.
The Federico Mora Hospital in Guatemala is home to 340 patients, including 50 violent and mentally ill criminals, BBC reports.
According to the hospital’s director, Romeo Minera, only a minority of the patients have serious mental health problems. A total of 74pc of patients arrived to the hospital in need of some attention and care and should have stayed in their community.
A male nurse tells BBC reporter Chris Rogers that two or three nurses have to care for up to 70 patients. He said the only way they can cope is to sedate the patients.
The reporter describes how patients regularly soil themselves as they are too sedated to walk to the bathroom.
“There are puddles of urine on the mattresses, and the clothing on some of the patients is covered in their own faeces. The stench of human filth overwhelms me and I try desperately to stop myself from vomiting,” Rogers writes.
“We are secretly filming the director as he makes an astonishing admission - the guards sexually abuse the patients. The hospital, he says, is a big place "where anything can happen".”
Rogers describes how two former patients claim they were raped at the Federico Mora Hospital.
One woman told of how she was sexually abused by a male nurse while she was sleeping. She was 17 years old and a virgin at the time.
"Since I was sedated I wasn't aware of it - I didn't realise until the next day that I had lost my innocence. I was bleeding down my legs, so I realised that what had happened that night is that a male nurse had come in and raped me," she tells the documentary.
"You can never forget that experience. You store it in your mind. I still think of the patients in there."
Another patient, who said he was raped throughout the three years, said police officers, the patients, male nurses and some doctors ‘put the prettiest girls aside for themselves at night’.
Chris Rogers also saw an isolation room in the hospital for patients who become too violent to handle.
The room is two square metres with a small window. A man was sitting in the corner and the floor was covered in human waste.
Rogers is told of how one patient recently took his own life by climbing up to the window and hanging himself.
In response to the investigation, the Guatemalan government said the hospital "uses the minimum dose of sedatives as recommended by the World Health Organization" and defended conditions in the hospital.
Meanwhile, the US campaign group Disability Rights International (DRI) spent three years collecting evidence on the hospital and published the findings in a report in 2012.
The report explained that patients were denied medical care, exposed to serious and contagious illnesses and infections and - compounded by the "widespread" sexual abuse - were at risk of contracting HIV.
The DRI is currently bringing a legal case against the Guatemalan government to have the hospital closed down. The case will be heard in the autumn of 2015.
Our World: World's Most Dangerous Hospital broadcasts on the BBC News Channel at 14:30 GMT and 21:30 GMT on Saturday 6 December - or catch up online.