The online fraud cases involving two family-based criminal groups operating in northern Myanmar and targeting Chinese nationals have entered the prosecution stage, with funds involved exceeding 24.6 billion yuan ($3.45 billion), the Ministry of Public Security said on Wednesday.

The progress in the cases against the Wei and Liu families marks a major blow to the so-called "Four Families" criminal groups in Kokang, northern Myanmar.

Authorities said the four groups had used their influence to establish dozens of telecom fraud centers in Kokang, committing a range of crimes including fraud, illegal detention, extortion, operating casinos, organizing prostitution, and drug trafficking.

Suspects from the Ming family were recently sentenced in a first-instance trial, while the Bai family's case has now entered its first-instance proceedings, the ministry said.

Since 2009, the Wei family has been implicated in crimes that caused the deaths of eight Chinese citizens, involving fraud-related funds exceeding 5 billion yuan, gambling funds surpassing 9 billion yuan, and illegal profits of more than 19 million yuan from organizing prostitution, according to the ministry.

The Wei family faces multiple charges, including fraud, intentional homicide, intentional injury, kidnapping, extortion, illegal detention, operating casinos, organizing prostitution, drug trafficking, harboring drug users, and organizing illegal border crossings.

The Liu family, meanwhile, has been accused of fraud, extortion, illegal detention, running casinos, organizing prostitution, drug trafficking, and smuggling people across borders. Since 2018, the group has been linked to fraud-related funds exceeding 2.6 billion yuan, gambling funds of more than 8 billion yuan, extortion through nude chats amounting to over 17 million yuan, and illegal profits of more than 16 million yuan from organizing prostitution.

Since July 2023, when the Ministry of Public Security launched a special operation to crack down on telecom fraud connected to northern Myanmar, China and Myanmar have carried out a series of joint law enforcement actions, leading to the arrest of more than 57,000 Chinese nationals suspected of fraud-related crimes.

In October 2023, under unified command from the ministry, Chinese authorities arrested nine key suspects from the Wei and Liu family groups at the Yunnan border. In December 2023, police issued public bounties for other major suspects, including Wei Huairen and Liu Zhengxiang, after gathering extensive evidence of their crimes.

According to a video aired by China Central Television, Wei Huairen said during interrogation that Chinese workers were considered "the most valuable resource" for the fraud groups. "The purchase price for a Chinese employee has risen from the original 20,000 yuan to more than 300,000 yuan," he said. "If Chinese workers at these fraud centers want to return home, they must pay a ransom of several hundred thousand yuan before their bosses will release them."

Investigators said the families stationed armed personnel at the fraud compounds to maintain control and suppress resistance from lower-level employees. Those who failed to meet fraud quotas, broke management rules, or attempted to escape were subjected to corporal punishment or detention. Some were even killed as a way for senior gang members to prove their loyalty to one another, authorities said.

Under the joint law enforcement mechanism, Chinese officers have entered Kokang four times to carry out investigations, despite the ongoing conflict in the region. They uncovered victims' remains, tools used in the crimes, and a large amount of critical physical and documentary evidence.

Zhang Hanyi, deputy director of the Quanzhou Public Security Bureau in Fujian province, said investigators traveled across 28 provinces to gather evidence from tens of thousands of individuals.

"Only a portion of the cases have been fully clarified," Zhang said, "as it is impossible to conduct a complete investigation due to objective conditions abroad."