Creepy Wikipedia

Ah, fair enough, I guess whether this is actually happening is a disputed point. Still, from the article it seems like it is not that much of a stretch from what apparently is not disputed about China's organ transplant practices, which is that there is a lot of organ transplanting going on in China despite a culturally driven absence of voluntary donations, a legalized practice of using the organs of executed prisoners which is officially acknowledged as the primary source of organs, and a market driven method for obtaining them with little accountability.

The commercial trade in human organs has also been a lucrative source of revenue for the Chinese medical, military and public security establishments.[26][27] Because there is no effective nationwide organ donation or allocation system, hospitals source organs from local brokers, including through their connections to courts, detention centers and prisons.[28]

If it's true that people with the authority to execute prisoners can easily get money by selling their body parts, and there isn't much oversight, it seems like a natural consequence that they might let financial considerations influence when and maybe even whether to kill these prisoners.