Vietnamese teenager Nguyễn Thiên Kai moved to Cambodia after she was promised a high salary for teaching people how to play online games.
But once she crossed the border, she was sent into a basement and instructed to scam people.
The 19-year-old realised she had been tricked.
"I had hidden my phone and managed to text my family to let them know what happened. But then the boss saw my phone and took it," she said.
"He read the texts to my family telling them to call the police, and he beat me and sold me to another organisation.
"It was terrifying. It was hell on Earth."
Ms Nguyễn is one of thousands of people across Asia who have been trafficked to Cambodia and forced to carry out online scams in a shadowy industry estimated to be worth millions.
Many victims were confined in casinos or dystopian compounds surrounded by thick coils of barbed wire, some of which have been linked to members of the Cambodian elite, according to extensive investigations carried out by local media outlet VOD as well as international news organisations such as Al Jazeera and ProPublica.
Not all scammers are victims of human trafficking in this murky scheme, but the reports found the vast web of criminality has netted unsuspecting workers from Taiwan, Indonesia, Vietnam, Malaysia, Thailand and conflict-riddled Myanmar.
The reports also found cyber scam compounds were largely run by Chinese criminal syndicates and the sophisticated online schemes have targeted people in China, the United States and Australia.
With its high rates of indebtedness and lack of employment opportunities, Cambodia has conventionally been seen as a "source country" for human trafficking, with Cambodians driven across borders into exploitation.
But this latest phenomenon is seeing Cambodia emerge as a destination country for human trafficking, including victims from typically wealthier nations.
"The COVID-19 pandemic caused large-scale loss of employment for many people across the world from even fairly developed countries, giving room to slavers who set up base in Cambodia to take advantage of their desperate situation," said Jacob Sims, country director for International Justice Mission Cambodia.
Ms Nguyễn's captors demanded a ransom of $US3,400 ($5,000) — an amount her family couldn't afford. They reached out to an anti-trafficking activist on social media who paid a sum to free her in July.
Her ordeal lasted 10 days, but others have been held for months, sold multiple times and have been tasered or subjected to other ill-treatment.
"It was only 10 days for me and it was an awful experience," she said.
"I'd like to let people know, families, young people … don't be tempted by offers of high salaries — it's never a real offer."
What are 'pig-butchering' scams?
During Sydney's lockdown last year, Vanessa decided to study Mandarin and joined a language-learning app.
There she met her scammer, who claimed to be from Hong Kong and asked for her WhatsApp number. They began chatting frequently over a three-week period.
He'd talk about his morning run, they'd share photos of food they were eating, he'd speak to her in Chinese, and – sprinkled throughout their chat history but never the main focus – he'd talk about his cryptocurrency investments.
She doesn't know if her scammer was based in Cambodia, but the "pig butchering" she experienced can happen in cyber slavery rings operating there.
"Pig butchering" is a translation of the Chinese term "sha zhu pan" and draws its name from the concept of fattening up an animal for slaughter.
In practice, scammers follow sophisticated scripts to earn their mark's trust, then encourage them to download a fake investment app.
At first, they might be able to withdraw their money, but the Global Anti-Scam Organisation (GASO) describes this as a "psychological trick" to build trust, and a hallmark of the scam is that the scammer almost never asks for money directly.
Vanessa, who now volunteers with GASO, said her scammer encouraged her to invest in a cryptocurrency platform and she saw a quick succession of profits over three days.
But then she got suspicious.
A reverse-image search of photos he sent her showed his face belonged to a model and was popping up on various websites.
"I was like, 'What the hell is going on? How does this even exist?'"
"It definitely did feel like betrayal. We didn't have a romantic relationship or anything, but he was a really good friend. There were loops of denial.
"When you're speaking to these scammers, it's like you're living in a bubble. And then once I found out … this bubble just burst. And my vision was clear."
Vanessa's case is rare in that she didn't lose any money. But she said other Australians have reported losing hundreds of thousands of dollars.
Australians lost $2 billion in scams in 2021, according to the Australian Competition and Consumer Commission.
That includes more than $701 million in investment scams and $142 million in romance scams. "Pig-butchering" scams often combine the two, according to GASO.
Between January and May this year, Australians lost $113 million to fraudulent cryptocurrency investments.
GASO said while over-55s were often perceived as susceptible to fraud, the average age of victims in these scams was around 30, and many were women with successful careers.
Vanessa said scam victims were sometimes strung along for months and the depth of deception was devastating.
"They were already talking about marriage and having kids and buying houses … It's so sad."
But she also felt for people on the other side of this industry.
"I really empathise and sympathise with the scammers that have been forced … or have been trafficked into doing this scam," she said.
Trafficked from Indonesia and Taiwan
In August alone, 241 people from Indonesia were repatriated from Cambodia after being trafficked to run online scams.
Fachri — not his real name — was one of them.
The 19-year-old was lured to the coastal town of Sihanoukville for a lucrative marketing job with an investment company, where he was told he could earn up to $2,200 a month.
Fachri's first task was to create fake accounts on various social media platforms using "seductive photos of beautiful women".
Using these fake accounts, he was told to "find customers" by adding new friends on social media and communicating intensively with them, before convincing them to put funds into investment platforms or online gambling.
"If the customer's deposit has reached $10,000, usually the money will no longer be able to be withdrawn," he said.
The demands of the work escalated — soon he was forced to work 14-hour days, seven days a week, and was ordered to extract a total of $55,000 per month from his marks.
Fachri said he finally decided to notify authorities after he saw three of his colleagues being held captive and feared he would meet the same fate.
"We reported it to the Indonesian Embassy through their Facebook and Instagram accounts … when the company found out, 10 workers were summoned and threatened to testify that everything was fine or they would be transferred to another company," he said.
"Knowing our friends were being threatened like that, we all, around 130 of us, finally rebelled."
He shared footage with the ABC of dozens of Indonesians protesting to supervisors, who were holding what appeared to be batons.
Fachri said they were thrown out on the street one by one.
"I was told to leave at 10pm, alone, my passport was torn up, my cellphone was reset, and I was just kicked out."
Eventually, he found local police who called the Indonesian Embassy.
Taiwanese woman Yu Tang, who asked to use only her first name, was recruited to work in Cambodia's casino and gambling industry in April this year.
But when she and others arrived in Cambodia's capital, Phnom Penh, their passports were confiscated.
"The first day we arrived, one of the guys told them we wanted to leave," she said.
"The man in charge just grabbed his hair and started to beat him and hit him with an electric shock."
She was taken to Sihanoukville, which had rapidly transformed into a casino hub after an injection of Chinese investment.
"They told me to invite my friends over for a vacation. They said if I managed to get 20 people over there, I'll be able to leave," she said.
"But everyone knows that's not going to happen. They wouldn't let us go even if we got 20 people. They would only sell us to other companies."
She escaped after three days. She said she left a message for Sihanoukville's governor on Facebook and shortly after, authorities were sent to her location and she was released.
But many remain trapped for far longer and around 40 people have now contacted her seeking help.
Rescue missions for Taiwanese people are further complicated because there is no diplomatic office in Cambodia, which recognises Beijing.
"I'm not afraid of telling people what happened. I feel like I'm just telling horror stories. It's just terrifying to me that in our civil society in the 21st century, such things still happen."
Ngô Minh Hiếu, a former cybercriminal once jailed in the US who now works for the National Cyber Security Centre in Vietnam, said not all scammers were forced to do the work, but thousands were.
"It's worse than prison. You get beat up every day and they treat you very badly. It's modern slavery.
"We are all human beings, but those people, they treat the people like animals, they don't see them as human."
What is Cambodia doing about it?
For months, Cambodian officials denied there was a human trafficking problem plaguing the country.
But Cambodian Deputy Prime Minister Sar Kheng, in a statement late last month, acknowledged foreign nationals had been trafficked into the country and subjected to abuse, and said authorities had rescued 865 victims.
The change in tone came more than a month after the US State Department downgraded Cambodia to a tier three country — its lowest rating — in its annual Trafficking in Persons report.
"Corrupt officials often thwarted progress in cases where the perpetrators were believed to have political, criminal, or economic ties to government officials," the report said.
The National Committee for Counter-Trafficking (NCCT) permanent vice-chair, Chou Bun Eng, told the ABC what was unfolding was "a new dangerous crime" and one that all countries in the region would need to resolve together — Cambodia alone could not prevent it.
"These operations have discredited Cambodia, however, please consider carefully that we are also the victim country," she said.
Some Cambodian officials previously claimed that alleged reports of trafficking and abuse were simply labour disputes, and Ms Chou said authorities had investigated some cases they claimed were fabricated or fake.
"So the accusation that all the cases are human trafficking is not true," she said.
Mr Sims from IJM said close coordination between law enforcement and victim support between the Cambodian government, UN bodies, NGOs and regional government was needed "to effectively respond to the magnitude of this crisis".
"Given the complexities of forced criminality, strong victim identification is also key to differentiate victims from illegal immigrants and perpetrators," he said.
"Action from leading social media platforms and governments is desperately needed to: one, reduce the inflow of people being fraudulently recruited via the internet and two, raise awareness about the risks of accepting unverified employment opportunities in foreign countries."
Meta, the parent company of Facebook, Instagram and WhatsApp, is aware of these scams and is sharing data with local law enforcement.
"At Meta, we have long prohibited this content and invest significant resources into keeping it off our platforms while also empowering people through awareness campaigns," a spokesperson said.
"We share the view of dozens of NGOs that the most effective solution is aggressive action by local authorities to find and prosecute the perpetrators of these heinous crimes."
An Australian Federal Police spokesperson said malicious cyber activity against Australians was increasing and the AFP was working proactively with Cambodian law enforcement to combat cybercrime.
They added Australia was not immune from human trafficking — there were 294 reports of modern slavery in the past financial year — and technology-facilitated trafficking was an ongoing threat.
