Two men tried to break into Mt Eden Prison on Sunday morning - fleeing when prison guards rushed to the scene.
Staff were alerted when the pair tripped an external wire alarm.
Department of Corrections' assistant regional manager, Grace Smit, says at no time did the pair manage to get inside the security fence.
She says she has no idea what they were up to but suggests they were either daredevils, or failed to realise April Fool's day had been and gone.
The two men are yet to be caught.
