The report, which was delayed after a legal challenge by Serco, also slammed the Corrections Department for its failure to detect the incidents through its official monitors.
It described a "difficult" relationship between Corrections monitors and Serco, in which the company often "pushed back" at criticism until the monitors effectively gave up.
Serco's "push back" over issues such as graffiti in cells, homebrew, and disorderly behaviour ended up distracting monitors from core problems at the prison, the report said.
In case anyone's forgotten, National's argument for private prisons was that they would be more efficient because contracts allowed for better monitoring of performance than simply running them through the public service. Instead, what actually happens is that private providers simply refuse to abide by those portions of the contract, and fight tooth and nail against them, while of course demanding an inflated price for this "better monitoring". And the net result is that we pay more for worse services than we would get if the government simply delivered them itself.
A sensible government committed to evidence-based policy would acknowledge this and give up on privatisation, because it simply doesn't work. If it is more profitable to cheat than deliver the service, then that is what providers will do (as even a casual glance at Serco's behaviour overseas would have shown). If National doesn't do this, then we can only conclude that its support for privatisation is dishonest, and aimed at channelling public money to donors and cronies rather than giving us better government.