South Korea arrests 23 over USDT laundering for Cambodian fraud network

South Korean authorities have dismantled an alleged cryptocurrency laundering operation that moved 16.8 billion won ($11.1 million) through USDT transactions and exchange transfers on behalf of a Cambodia-based phishing syndicate.

According to local news outlet Newsis, the Seoul Metropolitan Police Agency’s criminal investigative division has referred 23 suspects to prosecutors on charges including violations of the Foreign Exchange Transactions Act and the Act on Reporting and Using Specified Financial Transaction Information. Two alleged key figures, identified only as A and B, were arrested and detained.

Police said the group handled proceeds generated by a Cambodia-based phishing organization, moving funds through domestic and overseas cryptocurrency exchanges. Investigators allege that, acting under instructions from a suspected ringleader identified as C, the network purchased Tether (USDT), transferred assets between exchanges, and carried out illegal foreign exchange transactions between February 2024 and April 2025.

After examining more than 11,300 accounts linked to the laundering operation, police uncovered 265 cases of voice phishing and investment fraud worth roughly 25.7 billion won (approx. $17 million), according to police. Authorities said those accounts were used to route and disguise criminal proceeds before they entered the financial system.

Seoul police have also secured pre-indictment seizure and forfeiture preservation orders covering about 650 million won (approx. $430,000) in alleged criminal proceeds obtained through the scheme.

Still at large, the suspected organizer remains under an Interpol Red Notice as authorities continue efforts to locate and apprehend him.

Police widen scrutiny of crypto-based money laundering

A separate part of the investigation led to the arrest of 33 additional individuals accused of operating illegal currency exchange services using cryptocurrency.

According to police, those suspects accepted commissions from foreign tourists and acquaintances, purchased USDT through domestic and overseas exchanges, transferred the assets between platforms, and later converted them into foreign currency or Korean won for clients. Authorities said the transactions involved about 6.3 billion won (approx. $4.2 million).

A police official cited by local media warned that conducting cryptocurrency transactions on behalf of others or exchanging digital assets into fiat currency for third parties can also be punishable under South Korean law.

The case arrives as South Korean authorities continue to expand enforcement efforts against crypto-related financial crime. Earlier this month, blockchain analytics firm Chainalysis announced a cooperation agreement with the Korean National Police Agency that includes investigator training, certification programs and practical exercises focused on virtual asset crimes such as fraud, money laundering and cross-border theft.

Authorities have also established a dedicated task force targeting crypto-based money laundering, with investigators expected to focus on unregistered exchange operators and the movement of funds through stablecoins such as USDT.

Recent enforcement activity has extended beyond criminal investigations, and South Korean police have recently searched crypto exchange Bithumb’s offices as part of a separate probe into allegations that lawmaker Kim Byung-gi used his political influence to help secure employment for his son at cryptocurrency companies.