Private prison operator Serco is facing fines of more than $1 million over failings at Mt Eden prison.
Serco is paid about $31.5m a year to run the jail.
About $3m of that is made up of performance bonuses and fines can only be deducted from that, TV3 News reported tonight.
Documents released to the TV network broke down the fines Serco is facing or has already been slapped with over the past year.
It does not include any action over allegations of fight clubs and contraband at the prison.