A spokesman for Serco, which runs the facility, said another prisoner had attacked another inmate this morning.

“Our staff immediately took action to protect the victim and subdue the attacker.

“Hato Hone St John was immediately called and the prisoner was taken to hospital in a stable condition. The incident was also reported to the police who attended the scene.”

The spokesman said assaults in prison were illegal, unacceptable and would not be tolerated.

“Any perpetrator should expect criminal charges as well as disciplinary action in prison. All incidents are reported to the police.”

Police said an investigation was ongoing to determine how the inmate was injured.

“At this early stage in our investigations we do not have any further information.”

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