Queensland Police are investigating the sudden death of a security guard at Gympie Hospital.
The 46-year-old man had been restraining a mental health patient in the hospital's emergency department on Sunday before he died.
At one stage the pair fell to the ground, witnesses said.
By the time police arrived, the guard was reportedly out of breath and died a short time later.
Police investigations are continuing but the exact cause of death is not yet know.
In a statement to 7 News, Sunshine Coast Hospital and Health Service said: "Our condolences are with his family at this difficult time. We are providing support to family members and co-workers. No other statement will be made at this time."
News break - May 15