At 40, he is still haunted by the horror he lived through when he was just eight.

"When the lights were turned off, that's when the sexual abuse started," he says.

Han is one of thousands of victims of what human rights groups call one of the most shameful human rights abuses in recent South Korean history.

He wants the truth to be known and those responsible, or those who turned a blind eye, to be held accountable. He and others who suffered alongside him want closure.

Inmates eating at Brothers Home, a state welfare facility created to clean up the streets and house "vagrants" ahead of the 1988 Summer Olympics in Seoul.

Brothers Home

Brothers Home was a state-subsidized welfare facility in the southern city of Busan, operating in the 1970s and 1980s, created in the wake of presidential directives to clean up the streets and house "vagrants" ahead of the 1988 Summer Olympics in Seoul.

The original plan was to take them in, feed, clothe and educate them and release them after a year. The reality was far more brutal.

Less than 10% of those taken in were "vagrants," according to a 1987 investigation by a local prosecutor. The others were gum sellers, shoe shines, drunks, even children, forcefully detained by police and carted off to the homes.

Han was just eight-years-old when his father left him and his 10-year-old sister at a local police station, after he struggled to care for them on his own.

They were immediately transferred to Brothers Home. The beatings started the next day.

"My face was covered with blood, severely swollen," he says. "I couldn't eat properly for three days because I was beaten so badly. But then a survival instinct kicked in, I began to adjust."

Han describes beatings with clubs, water torture and frequent sexual abuse by the guards -- often inmates themselves who had been promoted to positions of authority.

"From the moment you open your eyes to the moment you fall asleep, there's abuse. If I suffered today, others will suffer tomorrow."

Deadly abuse

For some however, there was no tomorrow.

"We would go to church on a mountain-top once a week," Han says. "On the top of the mountain, there would be a graveyard behind the church, there were a number of unmarked graves that had obviously been dug up and covered over recently."

Han himself saw at least four inmates beaten to death, the images of their violent demises still haunt him.

Kim Yong-won confirms these brutal details. Once an eager young prosecutor from Ulsan district, the alleged abuse at Brothers Home stopped when it did thanks to his efforts.

"I went pheasant hunting one day (and) saw people in shabby clothes working outside with guards watching them closely, holding clubs," he says.

"I knew I had stumbled on a serious crime, so I started to investigate."

Kim raided the Brothers Home alongside detectives, where they found thousands of inmates detained against their will. "It was a perfect detainment facility, not a welfare facility, locked from the inside and out ... there was a hospital ward where patients who had clearly received no treatment at all were locked up."

But Kim says his investigation was restricted and sabotaged by his superiors from day one.

Guards watch as inmates work in fields.

Cover-up?

The owner of Brothers Home, Park In-geun, was a powerful man, says Kim. He had been awarded two state medals for social welfare achievements and had friends in powerful places.

Park did not respond to repeated requests for comment but in an autobiography he denied all accusations of wrongdoing.

"So I started my investigation Friday night and got the arrest warrant Sunday morning," Kim says. "But then the Mayor of Busan called me. He said 'you cannot arrest director Park, you should release him.' Of course, I refused, but that was just the start of the pressure."

Busan City Hall and the Ulsan Prosecutors Office did not respond to repeated requests for comment.

Park was eventually sentenced to two-and-a-half years in prison for embezzlement and minor charges after a lengthy legal battle.

When asked by CNN why there has not been a new and transparent investigation as demanded by the victims, the South Korean Interior Ministry said, "past affairs are very complicated and need a special committee to conduct the investigation."

A bill would need to be passed in parliament to set up such a committee, something opposition lawmakers have been pushing for for two years.

Inmates from the Brothers Home work at sewing machines.

Hoping for justice

Brothers Home was shut down in 1988. Han's sister and father were pushed onto the streets despite obvious mental issues, he says. They have been in and out of mental institutions ever since.

Han moved home to be closer to the mental hospital they currently live in, he still visits regularly to bring them snacks and coffee. Their meetings are strained, the physical and mental toll it takes on Han is clear.

He is angry at what was done to him and his family, angry at having "to live such a purposeless life, not being treated like a proper human being."

"I do resent the government, and they have to accept criticism to be able to look at this issue properly," he says.

Han and his fellow victims want the government to open a public investigation to acknowledge a shameful chapter of South Korea's history, and to allow those who suffered the brutality of Brothers Home to find closure and, hopefully, some peace.