(Bloomberg) -- South Korea confirmed more cases of “abnormal” foreign-exchange transactions, mostly related to cryptocurrencies,  the nation’s financial watchdog said.

The Financial Supervisory Service discovered an additional $680 million of “abnormal” money transfers, taking the value of confirmed unusual transactions found since June to $7.2 billion, it said in a statement Thursday. Most transactions have involved funds transferred from cryptocurrency exchanges to local companies before the money was sent overseas, the FSS said.

Of the total, 72% of the funds were transferred to Hong Kong, 15% to Japan and 5% to China, the FSS data show. The probe, which has so far involved 82 companies, found that 82% of transfers were in US dollars, with the Japanese yen accounting for 15%. Transfers from Shinhan Bank, Woori Bank, Hana Bank, Kookmin Bank, Nonghyup Bank and seven other Korean banks were investigated, FSS said.

Read more: Crypto Takes Leading Role in Illegal South Korea Currency Trades

The FSS said it aims to finalize the probe into the 12 banks by the end of October, and it will take strong measures if the investigation shows that lenders haven’t complied with regulations.

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