Cut Thi Oanh, 32, a resident in Ky Son District of Nghe An Province, is under investigation for "human trafficking."

According to investigators, Oanh was tricked and sold to China, where she was forced to marry a Chinese man in 2013.

Three years later, she returned to Vietnam and applied the same method to deceive women without jobs or a stable income in Ky Son, promising them a better future in China.

Two victims aged 30 and 36 eventually allowed Oanh to take them to the neighboring country.

Oanh then sold both to Chinese middlemen for VND370 million (almost $16,000), giving each women VND15 million while pocketing the rest.

The two were then forced into marriages with Chinese husbands.

In late July, the two women escaped home and reported Oanh to police. It remains unclear whether any children were born in the interim.

In the first half of this year, Vietnam had uncovered 60 cases of human trafficking involving 90 victims.

The country has recorded over 3,400 victims of human trafficking since 2013, over 90 percent women, children and those from ethnic minority communities, Nguyen Xuan Lap, head of the ministry's Department of Social Issues Prevention, said at a conference in November last year.

According to the Chinese Academy of Social Sciences, a think tank, around 40 million men in China need to look abroad for a wife as of this year. This is a direct result of the nation’s former one-child policy, which has seen families abort female fetuses for decades.

Hundreds of thousands of women from Vietnam, Cambodia, Laos, and Myanmar have gone to China to wed local men, activists say. Some end up happily married, but many others suffer violence and forced labor.