A pregnant 12-year-old girl who went for a medical checkup last week had been trafficked from Vietnam and sold to a Chinese man, public prosecutors said on Monday.

The People’s Procuratorate of Xuzhou, the city in China’s eastern Jiangsu province where the girl was brought to the hospital by her “husband” and his mother, published the news on their public WeChat account. It said the girl had been abducted in her native Vietnam and sold in May to a 35-year-old man for 30,000 yuan ($4,500).

The news first came to light on Oct. 4, when a Weibo microblog with photos of the girl in the hospital went viral. Hashtagged posts on the topic had been viewed more than 3.3 million times as of Tuesday afternoon. In September, a similar case involving a 10-year-old girl also spawned a flurry of social media reactions, with many people mocking the victim and her situation.

On the evening of Oct. 4, local police posted on Weibo that they suspected the girl was a victim of human trafficking, and that they had taken “related persons” to the police station. They wrote that because the girl was foreign, they could not communicate with her.

In Monday’s report, the procuratorate said the girl was abducted in 2014 by Vietnamese traffickers and first sold to a village in Henan province, central China. She was purchased by the man in Xuzhou in May. She was three months pregnant when she visited the hospital earlier this month. A doctor reported the case to the police, who are still investigating.

The procuratorate said that the suspect and the girl “lived together as husband and wife,” but Zhang Zhiwei, a lawyer who specializes in abduction cases at Beijing Bairui Law Firm, told Sixth Tone that due to the girl’s young age, she is legally considered a minor.

Zhang also said that many suspects go unpunished or receive short sentences for trafficking women or children and keeping them as sex slaves. “In the past, buyers caught up in trafficking had immunity from punishment,” he said, adding that new provisions to the law that came into effect late last year now allow for criminal punishment of those who purchase trafficked women or children.

“But buyers still don’t receive severe punishments. In this case, the buyer could just be sentenced to fewer than three years in prison,” Zhang said. 

He also said that although any sexual relationship between the suspect and the girl for legal purposes constitutes rape due to her young age, the man was only charged with trafficking, not rape.

China is faced with a gender imbalance after decades of strict family planning policies and a traditional preference for sons. Men outnumbered women by 33.6 million at the end of 2015. As a consequence, many men cannot find a partner, and some look to developing nations in Southeast Asia for brides, though reliable numbers are hard to come by.

Vietnamese media reported that the country’s embassy in China freed 26 Vietnamese women in 2015 who had been trafficked to China as sex slaves. The embassy was made aware of another 28 trafficked individuals but could not save them.

(Header image: Patrick Foto/Moment/VCG)