Kim Bumjae, 52, and a Vietnamese woman, Nguyen Thi Huong, 27, were arrested for questioning about appropriating property by fraud, the police said.

Kim Sung Hun, general director of Korean financial firm IDS Holdings, told Kim Bumjae in 2015 that his foreign exchange firm had branches around the world and asked him to open a branch in Vietnam and become its representative.

The branch was to accept investments and transfer them to South Korea for the parent company to invest in its foreign exchange business.

Kim Bumjae set up nine companies and a multi-level marketing system to attract investments, and organized foreign exchange classes to gain investors' trust.

But an investigation by the police found that he never transferred to Korea the money he collected from investors, and is thought to have misappropriated the amount left after paying interest and expenses.

Huong assisted him in creating two companies and running them.

The police said 119 people had invested over VND80 billion, and complained to them when they suspected their money had been swindled.