JOIN USA specialist search group and a police negotiator were sent to the hospital. The fire service personnel also joined the search, equipped with thermal imaging devices.
Half a dozen patients had to be moved out of the area where the man was caught, said hospital spokesman Mark Fenwick.
The 25-year-old was discovered in the roof space of the hospital and was dragged out of the confined space about 3.45 p.m. by one of several police officers.
"He was found hiding in the ceiling above the admission and planning unit, which is connected to the emergency department. We had to move patients out quickly when he was located," Fenwick said.
"We don't know what his movements have been. After being removed from the ceiling, he was given some treatment for a cut on his hand. He was then given over to police custody," Fenwick added.
However, when he was recaptured, he was naked as he had lost his hospital gown earlier in the day.