According to BBC, the woman, whose surname is Yang, lived in a padlocked 10-sq-metre cell and slept on a wooden bench.
Suggestions that she may have been there voluntarily have sparked debate about whether anyone will be held to account.
In recent months, online users have been up in arms over a number of cases of where elderly people have seemingly been neglected by their children. BBC reports.
Yang's conditions were exposed by a local woman who posted a video of Yang sitting by a cage door on the popular video service Miaopai.
"How could you make her live in here?" she asked of the woman's captors, "And not give her food?"
The video has been watched more than 1.8 million times since it was uploaded on 6 January, and many viewers have taken to popular microblog Sina Weibo to voice their outrage.
Tens of thousands posted using the hashtag #92YearOldKeptInPigsty, calling Yang's son and daughter-in-law "beasts" and "scum" and calling for some form of "retribution".
In 2014, a 90-year-old woman in central Henan province died after being subjected to similar conditions.
But Southern Morning Post reports that the woman's son, surnamed Wu, says his mum volunteered to move into the cage because her incontinence had "given them a great burden and she was worried about making the house smell".
Police say Wu and his wife are suspected of maltreatment, but if it turns out that Yang moved in voluntarily, they would be unlikely to face charges.