A few days later, she attended a virtual hearing before a Supreme Court judge, who was sitting in her book-lined chamber.

It was all fake – elaborate stage sets were designed to steal his money. Officials are worried that similar scams could soon emerge in other countries, including the US.

In this case, the fake police instructed Dr. Indra Taneja, a retired pediatrician, to keep her phone and laptop cameras on almost all the time, so that they could keep an eye on her every move. He was under threat from criminals who wanted to silence his testimony, he said.

The actors said officials need to verify that all their properties are clean. So in 16 days, he transferred $1.6 million from his accounts. Then the fake officials disappeared – along with his money.

“It was very reassuring,” said Taneja, a former assistant professor at Rutgers University’s medical school. “They did it very fast.”

The Indian scam, now common across the country, involves a Hollywood-level production that mimics the state machinery, tricking people with fake police stations and courtrooms. Victims are told they are under “digital arrest” for crimes such as money laundering or drug trafficking, and are ordered to remain on camera for several days or weeks while investigators allegedly verify their assets.

Experts say scams have begun to appear in American immigrant communities, although they are not as widespread as in Western countries, in part due to the lack of skilled scammers with American or other Western accents.

Officials say it’s only a matter of time before they spread even further. Stage sets modeled after those of the Federal Bureau of Investigation, the Royal Canadian Mounted Police, and law enforcement agencies in the UK and Australia are found inside scam centers in cambodiaAccording to Jason Tower, a senior expert at the Global Initiative Against Transnational Organized Crime.

“It’s basically like a global supermarket of fake police stations,” he said of the recent findings in the abandoned Scam Compound. “It’s incredible in terms of the numbers and how specific they are.”

Authorities say fake-police scam has ensnared thousands of people in India. He says these schemes prey on fear of the legal system and the social stigma associated with criminal investigation, implicating even highly educated professionals.

“This kind of sophistication is unprecedented,” said Pronab Mohanty, head of cyber crime and narcotics for India’s Karnataka state police. “It’s a whole different ballgame.”

The opposition follows a similar script. A scammer dressed in police uniform, sitting in an office bearing the symbol of a law enforcement agency, calls the victim on WhatsApp. The fake policeman turns on the video and starts accusing them of criminal activity.

There will soon be a “digital arrest,” followed by strict rules: keep video calls on at all times or check in regularly. Under virtual house arrest, victims are pressured to pay fines, bail payments or transfer funds temporarily held pending official audit.

Some victims have sold homes or depleted retirement portfolios. A Bengaluru-based technology executive was kept under fake digital arrest for an entire year and $3.4 million was extorted from him, police said. Scammers often seek to target wealthy and highly educated people. Many victims are elderly.

Retired Indian Army Colonel Frederick DeSa, 83, said the Mumbai Police woman who arrested him last October over WhatsApp for allegedly funding terrorists was completely credible.

She was always seen making calls from the police station wearing khaki uniform and cap, he said. Sometimes a junior constable would come into the frame and salute him.

“She spoke very good English,” D’Sa said. “She’s definitely educated. She’s not from the street.”

Bengaluru residents visited banks seven times in three days to sell their mutual funds. He transferred more than $60,000 to several accounts that he was told were linked to the central bank for auditing.

The policeman so frightened her by warning of serious legal consequences that she avoided telling her daughters or the bank managers.

“They drive you crazy,” said D’Sa, who was able to recover about $6,500 but never caught the scammers. “You don’t know what to do. You’re helpless.”

Law enforcement in several countries have stated that soundstages get even small details correct, which indicates that they are designed by people who have studied the real versions.

In Cambodia, officials recently took journalists on a tour of an abandoned scam center and showed off the remains of movie-like sets designed like Indian police stations. In one room, an emblem of the Greater Mumbai Police hung behind a table decorated with Indian flags. A police cap was placed on top of a cupboard, while a folded uniform was placed near a computer.

The stacks of forms carefully documented each victim’s personal information and assets, including bank balances and the ages and professions of family members.

Mohanty, a Karnataka state police officer, said operations targeting Indians often involve Indian nationals who were lured to work at the scam premises. Indians who were later freed from the complexes told police that they sometimes received training in acting and regional accents to better present themselves to law enforcement officers.

“It was like a magic show where the illusion was happening in front of us,” said R Rao, a 45-year-old accountant from the stricken southern city of Udupi. “You know it’s not true, but you still fall for it.”

Rao had prevented friends from falling prey to scams and advised clients against suspicious financial transactions. But when a man resembling a Mumbai Police officer appeared on video, he and his wife followed every instruction.

They checked their location every two hours, reported all their property, and kept the drama a secret from their two children. Following the instructions, Rao took a loan of $22,000 using the family’s gold jewelery as collateral and sent the money for auditing. He borrowed another $16,000 from his brother-in-law for bail.

Rao sometimes felt that something was wrong. But the scammers’ confidence and their ready answers to every question convinced them that it was real. “It was like hypnosis,” said Rao, who never withdrew any money. “He was a great actor.”

“They scared me, scared me, scared me,” she said. “They said, ‘We need to put you under surveillance for your safety.'”

He needed to keep his camera on almost constantly inside his New Delhi home. When she got out, she called the station, put the phone in her pocket and continued the call. At night they allowed him to turn off the camera to sleep.

On 26 December, he instructed him to wear a white shirt for a hearing before a Supreme Court judge. He appeared on screen in a black robe with a white collar, sitting at a table surrounded by books.

“They said, ‘You have to cooperate with us, otherwise you will be arrested,'” Taneja said. At one point, the judge even scolded the officers for being too lenient with him.

In 16 days, Taneja falls in love with the officers who change shifts at the fake station. She started calling them her children. In return, they called her “Mother”.

At night he read Hindu religious texts with the youngest officer, who asked him to send him passages he found particularly inspiring.

“They became like family members,” she said. “They said, ‘Madam, we want to clear this as quickly as possible. We are working day and night for you.'”

He sold the investments and withdrew funds from eight accounts. Many of the transfers were worth about $200,000 each.

On January 10, he called the authorities repeatedly, but no one responded. Finally one called back and said that she and her husband had been completely acquitted. They directed him to go to the nearest police station to initiate the refund process.

The officials present there were first confused, then worried by the amount he transferred. Taneja gave police details of the bank accounts to which he had sent the money and the authorities were able to recover approximately $220,000. But they never found out the scammers and all the remaining money was lost.

Taneja is still struggling to understand how she and her husband fell into the trap of scammers for more than two weeks. “We thought the police were trying to protect us,” he said.

Write to Shan Lee shan.li@wsj.com