A 55-year-old man marries a 20-year-old woman with mental illness in Zhumadian, Central China’s Henan Province on February 27. Photo: a screenshot of the video.

A video of a 55-year-old man marrying a 20-year-old woman who has mental illness in Central China's Henan Province has ignited heated debate on the internet, with netizens questioning the intention of the two families behind the marriage.

In a video posted by Toutiao News on Sina Weibo, the bride looks very young and is crying while the groom sitting next to her wipes her nose with a tissue.

The media reported on Monday that the man, surnamed Zhang, is 55 years old while the woman is 20 years old and has a mental disability. Zhang reportedly held a marriage banquet but they didn't register for a marriage license.

The video has gained a lot of attention from netizens, with many questioning the intentions of the two families behind the marriage, and asking why a woman with mental disability would marry a man who is 35 years older than her. Others asked whether the marriage is legal. 

Some netizens thought that maybe the father does not want to raise the daughter anymore, while others said that the two families are just trying to solve their own problems and they all have their own difficulties. 

For the two to live together is not against the law, but they cannot get a marriage license, as the woman's mental disability means she cannot clearly express her willingness to get married, said a local official in the government of Biyang County of Zhumadian City, Central China's Henan Province on Monday.

According to Article 1046 of the Civil Code of China, "A man and a woman shall enter into marriage freely and voluntarily. Neither party may compel the other party to enter into marriage against his will, and no organization or individual may interfere with the freedom of marriage."

However, based on relevant policies, if the two have children in the future, they can apply for a birth permit and register for a hukou (household registration). And the county government will actively help this special family, it said on Monday.

The groom said that the marriage had been approved by the bride's mother and that he would be a good husband. 

The father of the 20-year-old girl said that he did not ask her opinion about the marriage as she cannot speak due to her mental illness. The marriage was arranged by relatives and no fee was paid. "Both parties were satisfied," said the father in a video posted on Sina Weibo on Tuesday morning.

"It is hard to identify the case as an infringement of the girl's marital autonomy as stipulated by Chinese law as they haven't registered for a legal marriage," said Han Xiao, a lawyer based in Beijing.

But there may be other legal implications. "Since the woman has no judgment ability to tell whether it is her true intention, the sexual relationship between them may constitute the crime of rape as stipulated by the law," Han told the Global Times on Tuesday.