OCF general manager Dave Miller said in a statement just before midnight the area was contained and within the secure perimeter of the prison grounds.
"There is no threat to the wider security of the prison and no threat to public safety.
"Staff responded immediately to contain the incident and are currently talking to the man," he said.
"The prisoner has refused to comply, and Corrections has deployed its specialist working at heights team to undertake further containment of the prisoner and negotiate the prisoner down."
Fire and Emergency New Zealand crews were at the prison as a precaution.
There was no indication anybody had been injured.
"I would like to acknowledge the work of our frontline staff who are working in extremely cold and difficult conditions to safely manage and resolve this incident," Miller said.
Police had offered their assistance to Corrections, a spokesman said.
— Allied Media
