A video of a woman apparently locked against her will in a filthy shack has gone viral in China, prompting an investigation as well as a conversation about the country’s treatment of people with mental illness.

The footage, taken on 26 January, was posted to the video-sharing site Douyin the following day by a man who was shocked to find the woman locked in the rubbish-filled building in a village in Jiangsu province in the east of the country.