BANGKOK — Police in Thailand say they have broken up a money-laundering ring that transferred a total of 10 billion baht ($323 million), much of it linked to drug trafficking.

A Chinese businessman arrested in Bangkok, Qaing Ma, is believed to be a key figure in the operation, police Maj. Gen. Veerachon Boontawee said Thursday.

The suspect was flown by police to Chiang Mai in northern Thailand and was unavailable for comment.

Veerachon, head of the investigation division in the police region incorporating Chiang Mai, said Ma owns companies in Thailand that import Chinese agricultural tools and machines and send back Thai agricultural products such as frozen chicken. The businesses were used to carry out illegal money transfers, he said by telephone.

Ma "created a very complex network of money transfers to cover the origin of the money,” Veerachon said.

Arrest warrants were issued for 109 suspects in the June 16-22 police operation to shut down the network, he said. Police apprehended 74 suspects, including 13 already in prison, while 35 remain at large.

–2020, most of it linked to drug traffickers in Thailand and neighboring Myanmar. Myanmar is a major source of illegal drugs, most notably methamphetamine, for which Thailand is a major market and transit point.

Police began the money-laundering investigation after a seizure in January last year of 9 million methamphetamine tablets. They found bank books in the car from which they seized the drugs, and traced the accounts. They found Ma’s accounts served as both a source and destination for the money flows.

Ma’s companies also acted as an “underground bank” for more conventional Chinese businesspeople seeking to avoid fees by concealing money transfers, Veerachon said.

The suspects in the case include minor participants who each allegedly received 2,000-3,000 baht ($65-97) for allowing the ring to use their bank accounts.

All those involved face two charges so far: involvement with a transnational crime organization and money laundering. Each carries a penalty of 5-15 years in prison term and a 200,000 baht ($6,465) fine.

Veerachon said further arrests are expected.