The primary defendant, Dong Zhimin, was handed a jail sentence of nine years for the crimes of "abuse and illegal detention", according to a court in Xuzhou, a city near Shanghai.

In addition to Dong, five other defendants in the case were found guilty of abduction and trafficking, earning them jail sentences ranging from eight to 13 years.

Authorities said the woman, known by the name "Xiaohuamei", was abducted from her village in Yunnan, about 2,000 kilometres (1,243 miles) from where she was discovered.

The woman was then sold several times, including once in 1998 for 5,000 yuan ($727), before being forced to marry Dong, with whom she had eight children.

She was then imprisoned inside a rudimentary shelter with unsanitary conditions and a lack of protection from frigid winter elements.

She was later diagnosed with schizophrenia.

Harrowing images showing the woman with a chain and padlock around her neck in freezing weather emerged last year on video-sharing platform Douyin, drawing shock and outrage across China.

Authorities initially denied the case was linked to human trafficking, a relatively common phenomenon in the Chinese countryside, but higher-level investigations were launched after a public outcry.

And social media users Friday expressed outrage at what was seen as lenient sentences for her abusers.

"Only nine years in prison for having ruined someone's life," wrote one user of social media platform Weibo.

"It's far from enough, but it's proof that the internet is useful," wrote another. "If so many people weren't paying attention the issue would have never been settled."

China's one-child policy -- only relaxed in 2016 -- has led to a shortage of women due to a traditional preference for boys.

The resulting gender imbalance is believed to have fuelled human trafficking, according to a United States congressional report, with young women abducted and forced into marriage in villages where they are greatly outnumbered by men.