Cambodia says it has extradited to China a billionaire businessman accused of masterminding a vast cryptocurrency scam in which trafficked workers were lured to forced labour camps to defraud victims globally.

Chen Zhi was among three Chinese nationals arrested on 6 January after a joint investigation into transnational crime lasting several months, Cambodia said.

The US charged the 37-year-old, who was born in south-east China, last October with running internet scams from Cambodia that it said had stolen billions in cryptocurrency.

The US Treasury Department seized about $14bn (£10.4bn) worth of bitcoin it alleged belonged to him. The UK also sanctioned his global business empire, Prince Group.

US prosecutors said it was one of the biggest financial takedowns in history and the largest ever seizure of bitcoin.

The BBC contacted Prince Group for comment at the time. In the past, the Cambodia-based group has denied any involvement in scams. Its website says its businesses include property development and financial and consumer services.

Since Chen Zhi was indicted by the US on fraud and money-laundering charges in October, his whereabouts have been unclear.

But on Wednesday, the Cambodian authorities said they had arrested three Chinese nationals namely Chen Zhi, Xu Ji Liang, and Shao Ji Hui and extradited [them] to the People's Republic of China. The interior ministry statement did not say where Chen Zhi had been detained.

His Cambodian nationality had been revoked by royal decree last month, it added. The enigmatic tycoon had given up his Chinese nationality to become a Cambodian citizen in 2014.

According to the UN, hundreds of thousands of individuals have been trafficked to South East Asia, many lured by promises of legitimate jobs, only to be forced into running scams under the threat of violence. This exploitation often targets vulnerable populations in China.

Chinese authorities have been investigating the Prince Group since at least 2020, with claims linking the company to multiple online fraud schemes.

The extradition underscores significant global efforts against human trafficking and cybercrimes, revealing the scale and complexity of organized crime networks operating within and beyond Southeast Asia.