Nguyen Thi Chang, 27, was apprehended last October after officers caught two women having sex with Korean men in a hotel. The four of them told the police that Chang was the pimp.

Chang told the police she was working at Bomul Seoum Karaoke in Nam Tu Liem District. Kim Hack Bong, 45, a South Korean man, has been running this place since last January, she said.

Chang was in charge of managing women employees and guest reception at the place.

The employees were divided into two groups, one willing to have sex with customers and the other not willing. Those who consented could do so after working hours.

Kim told the police he only kept track of guest reception preparation and money management. He was not aware Chang was offering sexual services or had any role in it, he said.

Nguyen Duc Hiep, 36, whose name is on the business license of the karaoke parlor, said he only helped Kim because as a foreigner, he was not eligible to officially run such a business, and received no share of the profits.

The police did not press any charges against Kim or Hiep.

The Penal Code provides for warnings to sex workers and fines of VND100,000-300,000 ($4-13), while pimps can get between six months and five years in jail.