An Oregon hospital is under investigation by police following reports of multiple patient deaths.

On Friday, NBC5 News revealed that the police were looking into at least one patient’s death at the Asante Rogue Regional Medical Center in Medford.

Inside sources within Asante have since disclosed details surrounding the reported deaths, per NBC5 News. It is alleged that up to 10 patients died of infections contracted at the hospital.

The sources claim the infections were caused by a nurse who purportedly substituted medication with tap water.

It is alleged that the nurse was attempting to conceal the misuse of the hospital’s pain medication supply — specifically fentanyl — and intensive care unit patients were injected with tap water, causing infections that resulted in fatalities.