Thai police and military are looking for victims of a scam centre discovered close to its northern border in Cambodia.
Such operations in Cambodia, Myanmar and Laos have gained notoriety for cheating people around the world out of billions of dollars.
The syndicates behind these centres also carry out human trafficking.
A run-down apartment complex in O'smach, Cambodia, near the northern Thailand border.
The name O'smach Resort hides a dark interior and even darker past -- the scene of a brutal human trafficking, kidnapping and scam underworld that has traumatised thousands of lives.
The people behind this were highly organised. They have built an almost a perfect replica of a mainland China police station.
A fake background of a bank branch in Vietnam. Brazilian police, Australian police, Singapore police.
Backdrops and uniforms used to dupe victims into thinking they were talking to real officials and scamming them out of hundreds of millions of dollars.
Training rooms for callers, most of whom were grabbed off the streets or lured to Thailand by false job promises only to be captured and taken to work in scam centres, where failure to make money can lead to beatings or worse.
The words "No Money/Already took 297k scribbled on a whiteboard.
The site is now occupied by Thai troops, who captured the compound during recent military exchanges with Cambodia.
"I think this is very big, I think the biggest scam compound ever seen,
that we are able to get evidence (from)," said Police General Thatchai Pitaneelaboot. "Before it has been very difficult to get evidence from the Cambodian side, so I think that's very useful for us.
"What we are looking for is the victims of this scam centre. That is the most important. We would like to identify and bring them back to their relatives. Not only Thais, we are looking for other nationalities as well."
"They are well-organised," said Royal Thai Army Lieutenant General Teeranan Nandhakwang. "They have good infrastructure and systems and also the workflow and many, many tactics and techniques to do the scams."
Similar scam centres are believed to exist elsewhere in Cambodia, Myanmar and Laos, with these countries coming under pressure from China, the US and others to crack down on such criminal activities.
Last month, China executed 11 members of a Myanmar-based syndicate, including several from the same family.
On Monday, Chinese media reported that four members of the Bai family criminal group were executed for large-scale cross-border telecom fraud and violent crimes targeting Chinese citizens.