A mine worker has died after a physical tussle with police, security and hospital workers.

The 36-year-old suffered a medical episode while up to five staff tried to subdue him during a disturbance, WA Police Commissioner Col Blanch said.

WATCH THE VIDEO ABOVE: Man dies following tussle with police and medical staff inside hospital.

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The man had voluntarily admitted himself to Newman Hospital in the state’s Pilbara region after concerns for his welfare were initially raised by his employer.

Police were called to the hospital about 12.30pm on Thursday following reports he had been damaging property and staff needed help to sedate him.

“On arrival, police and hospital staff did wrestle with the male in an effort to provide the sedative,” Blanch said.

“During this time, the male suffered a medical episode.

“CPR was immediately commenced but tragically the male passed away after some time attempting to resuscitate him.”

Police believe he suffered a cardiac arrest but “we don’t know the cause of that at this time”.

Police were first called on Wednesday night by the man’s employer who said he was acting erratically, but officers could not find him.

He returned to his worksite about 2am on Thursday and was detained by police under the mental health act “as we had concerns for his welfare”.

The man agreed to be voluntarily admitted to hospital but later that day police were called.

“We understand that internal doors were ripped off or parts of the door were ripped off inside the hospital,” Blanch said.

He said at least two police officers, two medical staff and a security officer from the hospital worked to keep the man still.

‘Full and thorough investigation’

The homicide squad and internal affairs have travelled to Newman to look into the cause of the man’s death and the circumstances around it.

Body-worn cameras and CCTV vision will be used in what Blanch said would be a thorough investigation to “give the family the answers that they deserve”.

“At this time we will be treating it as a death in police custody,” Blanch said.

“Obviously our thoughts go out to the man’s family. We have notified his next of kin and his extended family and they are no doubt suffering significant grief at this time.

“Police are committed to conducting a full and thorough investigation.”

The police officers involved have been placed on three days of immediate leave, as is standard procedure, and Blanch said he would support them during what will be a long investigation process.