SEOUL, South Korea (AP) — Money laundering is not a good idea, as a South Korean found out when he or she put banknotes in a washing machine to remove possible traces of the coronavirus.

Officials say the loss was considerable.

The person living in Ansan city, near Seoul, placed an unspecified amount of 50,000-won ($42) bills in a washing machine earlier this year. Some of the money was seriously damaged, and the person reached out to the Bank of Korea to find whether it could be exchanged for new bills.

Under bank rules on the exchange of damaged, mutilated and contaminated banknotes, the per...