Police in northwest China are investigating five possible child trafficking cases at a hospital where an obstetrician was alleged to have sold a newborn baby.

On Monday, after the baby boy was returned to his parents, around 50 families had lined up outside a police station in Fuping County in northwest Shaanxi Province to report similar cases, The Beijing News reported.

Police didn’t specify the number of children in their latest investigation or whether it was the same doctor who was involved.

People involved in selling newborn babies to human traffickers were “morally degraded” individuals and “intolerable,” China’s top health agency said yesterday.

The National Health and Family Planning Commission was calling for severe punishments, and would impose stricter medical service management and strengthen medical ethics education nationwide to prevent such cases in future, Xinhua news agency reported, citing commisson spokesman Mao Qun’an.

The Fuping County case exposed “loopholes in some medical facilities” and “a few medical staff members’ lack of legal awareness,” local authorities said.

The obstetrician, surnamed Zhang, and five other suspects have been detained.