Torture, humiliation and coerced confessions are rampant in North Korea's pretrial detention system which treats people as worth "less than an animal", a rights group said Monday in a report on the country's opaque legal processes.
US-based Human Rights Watch drew on interviews with dozens of former North Korean detainees and officials to highlight what it called inhuman conditions at detention facilities that often amount to torture.
Nuclear-armed North Korea, accused of widespread rights abuses by the United Nations and other critics, is a "closed" country and little is known about its criminal justice system.
Mistreatment of detainees -- beating with a stick or kicking -- was "especially harsh" in the early stages of pretrial detention, interviewees said.
"The regulations say there shouldn't be any beatings, but we need confessions during the investigation and early stages of the preliminary examination," a former police officer said.
"So you have to hit them in order to get the confession."
Former detainees said they were forced to sit still on the floor, kneeling or with their legs crossed, for as long as 16 hours a day, with even a flicker of movement leading to punishment.
The punishments ranged from hitting -- using hands, sticks, or leather belts -- to forcing them to run in circles around a yard up to 1,000 times.
"If I or others moved (in the cell), the guards would order me or all the cellmates to extend our hands through the cell bars and would step on them repeatedly with their boots," said former detainee Park Ji Cheol.
Yoon Young Cheol, another former detainee, added: "There, you are just treated like you are worth less than an animal, and that's what you end up becoming."
Some female interviewees testified to rampant sexual violence at the facilities.
Kim Sun Young, a former trader in her 50s who fled North Korea in 2015 said she had been raped by her interrogator at a detention centre.
Another police officer sexually assaulted her by touching her underneath her clothes while interrogating her, Kim added, but said she had been "powerless to resist".
The report called on Pyongyang to "end endemic torture and cruel, inhuman and degrading treatment in detention" and urged South Korea, the United States and other UN member states to "publicly and privately pressure the North Korean government".
North Korean leader Kim Jong Un is the third generation of his family to rule the country, where state surveillance is widespread and dissent not tolerated.
The country already stands accused by the UN of "systematic, widespread and gross" human rights violations that range from torture, extrajudicial killings to running prison camps.
Pyongyang maintains that it protects and promotes "genuine human rights", and says there is no justification for the West to try to set human rights standards for the rest of the world.
It condemns international criticism on the issue as a smear campaign to undermine its "sacred socialist system".