Wandering down the unlit corridors of a six‑storey building behind the Royal Hill casino, each door opens onto a different world.

In one doorway there is a perfect replica of a Vietnamese bank. In another doorway there is an Australian police station. In a third corner a Chinese police officer’s shirt hangs as a silent reminder of the bogus authority that once occupied the space.

Motivational messages have been painted on the walls. "Money Coming From Everywhere" reads the Chinese characters on one sign. Discarded fake hundred‑dollar bills litter the floor, a stark visual of the scale of deception.

The hidden scam compound in O Smach

This massive scam compound sits just inside the Cambodian border town of O Smach. Thousands of men, women and children from a multitude of countries worked there under a harsh regime that regimented every minute of daily life, defrauding thousands of victims across the globe of their life savings.

In December, the Royal Hill casino was bombed by the Thai air force during a brief border clash between Thailand and Cambodia. The Thai authorities claimed that Cambodian drones were being launched from the casino premises. The workers fled, leaving behind uneaten bowls of noodles, half‑drunk cans of Coke and a lingering pungent smell.

Today, the Royal Hill complex stands empty, save for the Thai soldiers who now occupy the ruined structure. The windows lie shattered from the bombardment, and gaping holes have been blown through walls and roof, coating everything with a fine layer of dust.

The Thai military escorted the reporting team to the site because Thai officials wanted the world to see how large the scam industry had become in Cambodia. Thai officials said international assistance was needed to eradicate the scourge, while also using the visit as a secondary justification for the December air attacks on Cambodian targets.

The Cambodian government has protested the Thai occupation of its territory, but Thai officials argue that under the ceasefire both sides agreed to keep forces where they were when fighting stopped.

Royal Hill’s obscurity until the Thai takeover

What is remarkable about Royal Hill is not only its size but also the fact that almost nothing was known about it until Thai forces seized the compound.

The O Smach Casino, a separate complex across the road, has featured in news reports concerning fleeing scam workers who complained of abuses.

The owner of the O Smach Casino, Ly Yong Phat, is one of Cambodia’s most famous tycoons, known for a close relationship with the ruling Hun clan, headed by former prime minister Hun Sen. Ly Yong Phat has been sanctioned by the United States and other countries for alleged involvement in human trafficking and online fraud.

In contrast, the owner of Royal Hill, Lim Heng, keeps a much lower public profile. Lim Heng has never appeared on international sanctions lists, although, like Ly Yong Phat, Lim Heng has been awarded the prestigious title of Neak Oknha by Hun Sen – a title that requires a donation of at least $500,000 (£300,000) and places Lim Heng among a Cambodian elite of only a few hundred individuals.

The only somewhat unusual detail known about Lim Heng is a habit of paying respects at the cremation site of the notorious Khmer Rouge leader Pol Pot, which lies close to another of Lim Heng’s casinos on the northern border with Thailand.

Most of Cambodia’s tycoons amassed wealth by acquiring huge parcels of land after the end of the Cambodian civil war in 1991, leveraging ties to the ruling family. Initially they profited from illegal logging and plantations, later benefiting from a speculative property boom in the cities driven by Chinese investors.

In border regions like O Smach, casinos proved the most profitable venture, exploiting gambling bans in neighboring Thailand and China. Over the past three decades, the Cambodian government issued roughly 200 casino licences.

These licences attracted Chinese crime syndicates, which also ran lucrative online gambling businesses from the casino floors. In 2019, under pressure from China, Hun Sen banned online gambling. The subsequent COVID‑19 pandemic halted cross‑border travel, further cutting off traditional revenue streams.

Consequently, the syndicates switched to online fraud, luring young workers from around the world with attractive salary offers. Some recruits knew they would be part of scam operations; others believed they were signing up for clerical work or computer programming. Few realised until they arrived at the compounds how harsh the conditions would be.

The regime of punishment and control

At Royal Hill, documents recovered from the rubble, written in Chinese, detailed punishments for failing to meet targets. Failure to generate a "lead" – defined as beginning an online relationship with a victim – by the end of a day resulted in five strokes of a cane.

A worker who failed to produce any leads after three consecutive days received a minimum of ten strokes. Casual conversation with colleagues or failure to share intimate personal items such as photographs – tools used to build trust with victims – triggered similar punishment.

"Some people were electrocuted. Some were put into the black room. They have a room called The Black Room where terrible torture went on," said Wilson, a young Ugandan man who was recruited to work in Royal Hill in August.

Wilson says he was told he would be doing a digital marketing job in Malaysia. The reporting team spoke to Wilson from the Cambodian capital Phnom Penh, where he is now sheltered by a charity and trying to secure a way back to Uganda.

Wilson described being forced to work 15 or 16 hours a day, following scripts laid out by Chinese bosses, and using artificial intelligence to transform their voices and appearance.

"You are supposed to portray the character of a woman, who is 37 years old, rich, and who wants a husband. You chat to these older Americans with the intention of making them think you have fallen in love with them. So, in the script, there's a point where you break them emotionally. You build trust, and then later on you can lure them into buying the products," Wilson recounted.

Wilson says the workers were forced to keep working even during the Thai bombardment. "Every time we would hear a bomb – the building would sometimes shake – we would run out. We were scared. But then we had to come back in and work again," he recalled.

Further documents outlined similar scam scenarios in multiple languages, detailing how to gain victims' trust and reassure them about prospective "investments". The same documents listed a range of fines for lateness and other infractions.

Workers needed permission to use the toilet, and an "Employee Outing Registration Form" recorded every bathroom break taken by each worker on the days before the Thai attack, even noting the length of each break.

Fake law‑enforcement fronts

Next to a replica Brazilian police station, rows of booths lined with sound‑proof foam had been constructed. On the desks were handwritten notes in Portuguese reminding the scammers of the tactics they were to use to win over their targets.

A fake but convincing summons from the São Paulo police, apparently charging an individual with money‑laundering, was displayed – a tool commonly used to scare victims into transferring funds or revealing bank‑account information.

International pressure and governmental response

For years the Cambodian government ignored the growing international concern over the scam industry and the crimes linked to it. The 2025 U.S. State Department Report on human trafficking accused the Cambodian government of failing to make significant efforts to eliminate it, noting that no suspected scam‑compound operator or owner had ever been arrested or prosecuted.

When the United States imposed sanctions on Ly Yong Phat in September 2024 over links to scams and forced labour, the ruling Cambodian People’s Party – in which Ly Yong Phat is a senior figure – demanded that the sanctions be withdrawn, accusing the United States of violating Cambodian sovereignty.

This year, however, the government abruptly changed tack after sustained pressure from the United States, China and other countries to act against the scams.

Police teams have raided dozens of suspected scam compounds, and Prime Minister Hun Manet announced that the industry would be completely shut down by the end of April, saying it was destroying Cambodia’s economy and reputation.

The most dramatic move was the arrest and extradition to China in January of Chen Zhi, a young Chinese entrepreneur whom the United States and United Kingdom sanctioned the previous year, accusing Chen Zhi of running a huge network of companies funded by extensive fraud.

Chen Zhi had purchased Cambodian citizenship and risen to become one of the most influential figures in the country, serving as a personal adviser to Hun Sen. Chen Zhi’s Prince Group owned a national bank, an airline and extensive property developments.

For years Chen Zhi seemed untouchable. Yet following the arrest, video was published showing Chen Zhi being dragged, hooded and handcuffed off the plane that took him to China, where he now awaits trial on charges of operating a cross‑border gambling and fraud syndicate.

Chen Zhi’s humiliating treatment sent a signal that high‑profile figures in the scam industry might be sacrificed to save Cambodia’s reputation.

The authorities followed that with the recent extradition of Li Xiong, chairman of Huione Pay, an online payment system accused of laundering profits from scam compounds.

Aftermath and lingering doubts

Many of the scam compounds now lie empty. Police say more than 10,000 foreign workers have been repatriated. Others, such as Wilson, are still trying to find a way home.

However, there are good reasons for scepticism over the government’s claim that this marks the end of the scams in Cambodia.

Raiding scam compounds has been described as playing whack‑a‑mole. It is all too easy to move workers to new, lower‑profile compounds, and many thousands are believed to have chosen to stay in Cambodia.

Apart from Chen Zhi, none of the tycoons accused of hosting compounds behind their casinos has yet been touched. Ly Yong Phat, Try Pheap and Kok An are all wealthy and powerful figures who have been sanctioned overseas, yet continue to live comfortably in Cambodia.

In a supreme irony, senators Ly Yong Phat and Kok An took part in voting for a new law that the Cambodian government says will harshly punish those involved in scamming.

As for Lim Heng, the tycoon who built Royal Hill – until the Thai army moved across the border and captured his casino – Lim Heng’s name had never figured anywhere in the reporting and investigations of the scam business.