One man has been taken into custody
The Cork city centre hospital has triggered its emergency response plan while Gardaí have sealed off part of the hospital where the apparent attack occurred in the early hours of the morning.
One man has been taken into custody.
It is understood that the deceased is a male patient aged in his late 70s or early 80s.
The man in custody is in his 30s.
Other patients and staff raised the alarm when they discovered the elderly patient with critical injuries around 5am (Sunday) on one of the MUH wards.
The man in his 30s was discovered in an agitated state at the scene.
No weapon is believed to have been involved in the incident. It is unclear what triggered the incident and whether there was some kind of argument between the two men.
It occurred in the main section of the city centre hospital which is one of Ireland's oldest and best known acute teaching hospitals outside Dublin.
The hospital is almost 170 years old and sections of its main building date back almost 300 years.
Security staff and Gardaí were alerted when the man was discovered injured and the scene was immediately sealed off.
Desperate efforts were launched to assist the elderly man who was injured.
However, he was pronounced dead a short time later.
A full forensic and technical examination will now be conducted of the scene.
The man's remains will be taken to the Cork Morgue for a post mortem examination later today.
Garda sources stressed that the nature of their investigation will be determined by the post mortem findings.
A separate investigation is now underway by MUH into the incident.
Gardaí fear that the elderly man died as a direct result of injuries sustained in the incident with the younger man.