Briefing reporters and foreign delegates in Surin province, senior Thai military officials said the O'Smach complex had housed thousands of people, many of them victims of human trafficking who were forced to scam strangers or face punishment.
Soldiers later showed reporters around one of several buildings in the complex that were bombed and occupied by the Thai military late last year.
The six-storey building was strewn with documents, including long lists of what appeared to be potential targets and their contact details, as well as scripts for scam dialogues.
Among the items seized at O'Smach were 871 SIM cards, dozens of smartphones, counterfeit police insignia and police uniforms, the Thai military said.
Reporters visiting the complex saw several rooms set up to resemble police offices and uniforms of law enforcement of at least seven countries: Australia, China, India, Indonesia, Vietnam, Singapore and Brazil.
The set-ups served as essential to a scam where people are targeted by scam operators pretending to be officials or other authority figures.
Scripted approaches were meant to threaten arrest or other legal action unless instructions were followed.
O'Smach has previously been named as a base for scam operations including by the United States, which cited trafficking and forced criminality.
"The reason we are showing this place today is that we want the world to see how it's being used as a criminal base against humanity," Lieutenant General Teeranan Nandhakwang, director-general of the Royal Thai Army's Directorate of Intelligence, told reporters.
Touch Sokhak, a spokesperson for Cambodia's interior ministry, told Reuters Thailand had used scam centres as a pretext for military attacks.
He said Cambodia was carrying out a crackdown on scams and had pledged to eradicate the illicit industry before April.
Thailand and Cambodia ended weeks of fierce border clashes in late December with a ceasefire - the second in recent months - that halted the worst fighting in years between the two countries.
During the clashes the Thai military struck several casino complexes it alleged were scam compounds, saying they were also used to store weapons and launch attacks.
The December ceasefire stipulated that the warring sides would de-escalate tensions and hold their forces at the positions they occupied prior to the agreement.
That includes the compound on Cambodian soil now occupied by Thai troops.
Parts of Southeast Asia, including border areas between Thailand, Myanmar and Cambodia, have become hubs for online fraud in recent years, generating billions of dollars annually.
with AP
