Fifty nine persons were arrested in a crackdown by Chinese police on Beijing's 10 "underground banks", which illegally traded foreign currency and transferred about USD 22.6 billion across borders.
The cases involved nearly 140 billion yuan (USD 22.6 billion), said the police.
More than 400 policemen in September were dispatched to undertake the operation, which resulted in the arrest of 59 suspects; seizure of over 800 bank cards and more than 100 Internet banking digital certificates; and the freezing of 264 bank accounts, state-run Xinhua news agency reported.
A man, surnamed Yao, initially came under the police's radar in February.
Every transaction involved the exchange of Chinese currency yuan, equal to USD 50,000, the maximum limit an individual can purchase with within the country annually.
He had used various bank accounts to send the money abroad.
Over the past year, he transferred over USD 5 million overseas.
The police raided "underground banks" hidden in the districts of Chaoyang, Dongcheng and Xicheng in Beijing.
Through this breakthrough, illegal trading procedures, capital flow, business networks and other shady activities were uncovered.
The suspects transferred money online or by cellphone - rather trading in cash.
They often operated from their own homes and borrowed, rented or bought others' bank accounts.
"Underground banks", which run without financial supervision, not only threaten the economy and financial security, but also encourage smuggling, money laundering and state assets embezzlement, a spokesman for the Beijing Police said.
