In a statement, Otago Corrections Facility director Dave Miller said two Corrections officers were assaulted in one of the prison’s high-security units on Sunday.
A prisoner was being returned to his cell from recreation time in the yard when he assaulted an officer, Mr Miller said.
Another officer was also assaulted when they intervened.
The two staff members were seen by on-site health staff and were sent to an after-hours clinic for further checks.
Both were recuperating at home and being supported by the prison’s managers and welfare staff.
They were expected back at work next week.
The prisoner would be charged with misconduct and police would determine whether any criminal charges were laid.