BEIJING -- Following a US clue on drugs and money laundering, Chinese police have launched an investigation into a case involving illegal foreign exchange transactions, China's Ministry of Public Security said Wednesday.

The investigation has found that, since 2017, the suspect surnamed Tong started a car dealership in the United States and offered exchange services between Chinese yuan and US dollars. The operation later evolved into criminal activities including the illegal trading of foreign exchange.

Tong has already been arrested, and further investigations are underway, said the ministry.

The ministry noted that the case is a prime example of recent China-US anti-drug cooperation.