Thousands of people - the homeless, the drunk, but mainly children and the disabled - were rounded up off the streets of South Korea before the 1988 Olympics.
The treatment of the so-called vagrants has come under question in the past, but an Associated Press investigation has revealed that the abuse carried out at Brothers Home, the largest of dozens of such facilities, was much more vicious and widespread than previously known, based on hundreds of exclusive documents and dozens of interviews with officials and former inmates.
Yet nobody has been held accountable to date for the rapes and killings at Brothers because of a cover-up orchestrated at the highest levels of government, the AP found.
Two early attempts to investigate were suppressed by senior officials who went on to thrive in high-profile jobs; one remains a senior adviser to the current ruling party.
Products made using slave labour at Brothers were sent to Europe, Japan and possibly beyond, and the family that owned the institution continued to run welfare facilities and schools until just two years ago.
Thousands of traumatised former inmates have still received no compensation, let alone public recognition or an apology.
The few who now speak out want a new investigation.
The current government, however, refuses to revisit the case, and is blocking a push by an opposition lawmaker to do so on the grounds that the evidence is too old.
Choi Seung-woo was one of the thousands who suffered terrible abuse and even now, 30 years later, he still weeps when he recounts his experience at the Brothers Home.
When he was aged just 14, a policeman yanked down his pants and sparked a cigarette lighter near his genitals until he confessed to a crime he didn't commit.
Then two men with clubs came and dragged Choi off to the institution.
A guard in Choi's dormitory raped him that night in 1982 and the next, and the next.
So began five hellish years of slave labour and near-daily assaults, in which Choi saw men and women beaten to death, their bodies carted away like garbage.
Choi has attempted suicide several times and now attends weekly therapy sessions.
Once an orphanage, Brothers Home at its peak had more than 20 factories churning out woodwork, metalwork, clothing, shoes and other goods made by mostly unpaid inmates.
The sprawling compound of concrete buildings rose above the southern port city of Busan, its inmates hidden from view by tall walls and kept there by guards who carried bats and patrolled with dogs.
The horrors that happened behind those walls are inextricably linked to South Korea's modern history.
In the 1970s and '80s, before democracy, the country was ruled by military dictators who focused overwhelmingly on improving the economy.
In 1975, Park Chung-hee, father of current President Park Geun-hye, issued a directive to police and local officials to "purify" city streets of vagrants.
Police officers, assisted by shop owners, rounded up panhandlers, small-time street merchants selling gum and trinkets, the disabled, lost or unattended children and dissidents, including a college student who'd been holding anti-government leaflets.
They ended up as prisoners at 36 nationwide facilities.
By 1986, the number of inmates had jumped over five years from 8,600 to more than 16,000, according to government documents obtained by AP.
Nearly 4000 were at Brothers.
But about 90 per cent of them didn't even meet the government's definition of "vagrant" and therefore shouldn't have been confined there, former prosecutor Kim Yong Won told the AP, based on Brothers' records and interviews compiled before government officials ended his investigation.
The inner workings of Brothers are laid bare by former inmate Lee Chae-sik, who had extraordinary access as personal assistant to the man in charge of enforcing the rules.
The AP independently verified many of the details provided by Lee, now 46, through government documents.
Lee was sent to Brothers at 13 after trouble at school.
A year later, he was made personal assistant to chief enforcer Kim Kwang-seok, who like other guards at Brothers was an inmate raised to power by the owner because of his loyalty.
Many former inmates remember Kim as the facility's most feared man.
The AP tried repeatedly to track Kim down but could not find him.
Lee said he was present when Kim, a short, stocky man with sunburned skin, led near-daily, often fatal beatings at the compound's "corrections room."
The violence at Brothers happened in the shadow of a massive money-making operation partly based on slave labour.
The factories were ostensibly meant to train inmates for future jobs but by the end of 1986, Brothers saw a profit from 11 of them, according to Busan city government documents obtained exclusively by the AP.
View of the construction site of the Jeongseon Alpine Centre during the venue opening ceremony in January 2016 (Getty) Source: Getty Images
The documents show that Brothers should have paid the current equivalent of 1.7 million US dollars to more than 1,000 inmates for their dawn-to-dusk work over an unspecified period.
However, facility records and interviews with inmates at the time suggest that, instead, most of the nearly 4,000 people at Brothers were subject to forced labour without pay, according to prosecutor Kim.
Another probe at the time, quickly scrapped by the government, showed that "nearly none" of about 100 inmates interviewed received payment.
None of 20 former inmates interviewed by the AP received money while at Brothers either, though three got small payments later.
While owner Park In-keun raked in the money, the death toll mounted and the inmates struggled to survive.
Death tallies compiled by the facility claimed 513 people died between 1975 and 1986; the real toll was almost certainly higher.
Prosecutor Kim interviewed multiple inmates who said facility officials refused to send people to hospitals until they were nearly dead for fear of escape.
Most of the new arrivals at Brothers were in relatively good health, government documents show.
Yet 15 inmates were dead within just a month of arrival in 1985, and 22 in 1986.
A view of the construction site of the Alpensia Ski Junping Centre of the Pyeongchang 2018 (Getty) Source: Getty Images
Of the more than 180 documented deaths at Brothers in 1985 and 1986, 55 of the death certificates were issued by a single doctor, Chung Myung-kuk, according to internal facility documents, interviews and records compiled by Kim.
Chung, now dead, mostly listed the cause of death as "heart failure" and "general weakness."
Some inmates did manage to escape.
Park Sun-yi was snatched by police at age nine from a Busan train station in 1980 and sent to Brothers.
She had watched as the guards reserved their most ruthless beatings, the kind where inmates sometimes didn't recover, for those who tried to run.
But after five years, she said, she became "consumed with the thought that my life might be like this forever and that I might die here."
She and five other girls used a broken saw from the ironwork factory to file away bars on a second-floor window at night, little by little, reattaching them with gum each morning.
At last, they squeezed themselves out, scaled a wall embedded with broken glass and fled into the hills.
The unraveling of Brothers began by accident.
While pheasant hunting, Kim, then a newly appointed prosecutor in the city of Ulsan, heard from his guide about men with wooden bats and large dogs guarding bedraggled prisoners on a nearby mountain.
When they drove there, the men said they were building a ranch for the owner of the Brothers Home in nearby Busan.
Kim knew immediately, he said, that he'd stumbled onto "a very serious crime."
In January 1987, Kim led 10 policemen past the facility's high walls, imposing steel gates and gape-mouthed guards in a surprise raid.
Inside, he found battered and malnourished inmates locked in overcrowded dormitories.
FIle image of the interior of the Gangneung Curling Centre is seen in the Gangneung Sports Complex (Getty) Source: Getty Images
After the owner was arrested, he demanded a meeting with Kim's boss, the chief Busan prosecutor, who then supervised Ulsan.
A day later, Busan Mayor Kim Joo-ho, who died in 2014, called Kim to plead for Park's release.
Kim said he politely declined and hung up.
At every turn, Kim said, high-ranking officials blocked his investigation, in part out of fear of an embarrassing international incident on the eve of the Olympics.
President Chun Doo-hwan, who took power in a coup after Park Chung-hee's assassination, didn't need another scandal as he tried to fend off huge pro-democracy protests.
Internal prosecution records reveal several instances where Kim noted intense pressure from Chun's office to curb his probe and push for lighter punishment for the owner.
Kim had to reassure presidential officials directly and regularly that his investigation wouldn't expand.
Park Hee-tae, then Busan's head prosecutor and later the nation's justice minister, relentlessly pushed to reduce the scope of the investigation, Kim said, including forcing him to stop his efforts to interview every inmate at Brothers.
Park, a senior adviser to the current ruling party, has repeatedly denied AP interview requests.
His personal secretary said Park can't remember details about the investigation.
Despite interference, Kim eventually collected bank records and financial transactions indicating that, in 1985 and 1986 alone, the owner of Brothers embezzled what would be the current equivalent of more than 3 (m) million US dollars.
That came from about $10 million US dollars of government subsidies meant to feed and clothe the inmates and maintain the facilities.
However, Kim said, the chief Busan prosecutor forced him to list the embezzlement as nearly half the amount he had actually found so that a life sentence couldn't be pursued under the law at the time.
Kim said his bosses also prevented him from charging the owner, Park, or anyone else for suspected widespread abuse at the Brothers compound, and limited the prosecutor to pursuing much narrower charges linked to the off-site prisoners.
Kim demanded a 15-year prison term for Park.
After a lengthy battle, the Supreme Court in 1989 gave Park two-and-a-half years in prison for embezzlement and violations of construction, grassland management and foreign currency laws.
He was acquitted of charges linked to off-site abuse.
Only two guards received prison terms, one for one-and-a-half years and another for eight months.
Inmates released from the facility ended up homeless and in shelters and mental institutions; many struggle with alcoholism, depression, rage, shame and poverty.
In two years time the eyes of the world will once again be on Seoul as it hosts the Olympic games for a second time.
The few former inmates who have begun speaking out want justice for the way they were treated leading up to the previous games: an apology and an admission that officials encouraged police to kidnap and lock away people who shouldn't have been confined.
