Bad hygiene at the intensive care unit of a private Seoul hospital killed four newborn babies within two hours last month, police said Friday.
Five medical staff - two doctors and three nurses - at Ewha Women's University Hospital will be charged with involuntary manslaughter due to negligence over the deaths, officials said.
The incident is unusual for South Korea, which is highly technologically advanced and a major destination for medical tourism, particularly cosmetic surgery.
Blood tests on the four premature babies showed that they were all infected with the same drug-resistant bacteria, which resulted in septic shock, the Seoul Metropolitan Police Agency said.
All the infants showed drastic changes in their heartbeats and had bloated bellies, according to the National Forensic Service, which carried out the postmortem examinations.
"It is rare that deaths by a bacterial infection all come at about the same time," the NFS said.
They had either been given contaminated nutritional supplements, it concluded, or the supplements were contaminated during the process.