The suspect is already in a prison cell after being arrested on charges of murder and attempted murder last year. The victims are believed to be residents of a nursing home as well as private patients seen by the nurse.
It was the death of a patient in September 2017 that triggered the investigation. The patient swiftly died after being hospitalised and high levels of insulin were detected in the patient's blood. A 43-year-old nurse entered the frame as the main suspect. So far 21 deaths have been linked to the male nurse, who denies any involvement.
The chief public prosecutor of Namur insists that the suspect remains innocent until proved guilty: "It's hard to say whether a serial killer has been at work. We still face numerous questions."