These photos released on Tuesday show an inmate wearing restraint devices in one of the country's prison facilities. Courtesy of National Human Rights Commission of Korea

The National Human Rights Commission of Korea urged a prison warden to minimize the use of restraint devices, saying that “excessive use” of such equipment could be detrimental to the health of some inmates.

In a statement released Tuesday, the commission recommended against using more than two types of equipment simultaneously to gain control of a violent inmate unless absolutely necessary. It also called for the warden in question to strengthen monitoring of the inmates who might seek help for equipment-caused emergencies.

This comes after the commission's investigation of one of the nation's correctional facilities, where an inmate died in March after being forced to wear a helmet, handcuffs and leg irons after showing aggressive behavior toward another inmate.

The cause of his death remains unclear. But the commission said the pressure caused by the devices might have contributed to it, given that he had high blood pressure, hyperlipidemia and other underlying health conditions.

“Given that an autopsy report did not confirm the cause of death, it is difficult to conclude that the use of the protective equipment was the direct cause of his death,” the commission said. “But the victim was healthy an hour prior to the use of the equipment. Additionally, it was found that many problems may have contributed to his death, such as the simultaneous use of three types of protective devices, failure in monitoring the victim, flawed reasons for putting him in an isolated cell and no device installed there for emergency calls.”

On March 29, the inmate, scheduled to be released in two months, had a fight with another prisoner. In apparent anger, he tried to use violence against him and accidentally hit the leg of one of the prison guards trying to restrain him.

After being handcuffed for 45 minutes, he was returned to his cell. But he was later told by prison officers to put on restraint equipment — handcuffs, a helmet and leg irons, all at once — for trying to attack the same person. Then, at 4:51 p.m., he was put in a “protection room,” an isolated place set up for prisoners who need extra attention for the risk of self-harm among other reasons.

According to the rights commission, he started to show signs of pain soon after entering the place. He asked for help through the door, only to be ignored. Five minutes later, he passed out, security camera footage showed.

However, prison officers did not notice anything serious happening until 5:33 p.m. When he was taken to a nearby hospital, it was too late.

“The law on treatment of correctional institute inmates stipulates that protective (restraint) equipment should not be used as a means of punishment. As the name suggests, its purpose is protecting the person from harming others or themselves,” the rights commission said.

It pointed out that he could have survived it if the prison guards had responded earlier.

The commission asked the justice ministry to check all emergency call equipment installed at “protection rooms” of prison facilities nationwide to prevent similar incidents.