The illicit operations handled funds amounting to 10.4 billion yuan (US$1.3 billion; Ђ 1 billion), mostly in unauthorized foreign exchange conversions and money transfers, the Xinhua News Agency said, citing the Ministry of Public Security.
By the end of July, police had arrested 27 suspects linked to the black markets, the report said.
China's currency, the yuan, doesn't trade on world markets and the government restricts access to foreign currency, creating opportunities for underground traders to supply currency needed by tourists, investors and others.
The government has tried to reduce illegal trading by easing limits on how much foreign currency Chinese citizens can take abroad, the AP reports.
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