They have proposed charges against the three suspects – Nguyen Thi Huong of Hau Giang and Le Qui Luong and Dao Van Tuyen from the northern province of Hung Yen. The local prosecution agency will consider ratifying the charges.

Hau Giang police learnt about the case in February when the girls’ mother Nguyen Thi Dep informed them that 21-year-old Huong had cheated her and sold her daughters to brothels in China last November.

The girls, one 14 and the other 29 years old, managed to escape and called home for help.

They were brought home in March after the police cooperated with the Ministry of Public Security, their Chinese counterparts and those in the northern province of Lao Cai that borders China.

The girls told the police that they were first offered work at a café in Hanoi for VND5 million (US$282) a month each.

They were given VND950,000 to travel to Hanoi, where Huong and her husband Tuyen, 29, put them on a train to Lao Cai where the two sisters were sold to a man identified as Hung.

Luong, 25, acted as a go-between between Hung and the couple.

Hung, who the police are looking for, took the girls to China.

He forced them to have sex at a boarding house eight hours every night, sometimes with 10 customers, and pocketed all the money.

After several months the girls were sold again for 13,000 yuan ($1,900) and forced to do the same work for a while before being caught by Chinese police.

Hung paid the bail to get them released and forced the women into prostitution again to pay him back.

Reported by Mai Tram