There are calls for the Government to address the lack of mental health care in prisons.
Figures show there have been twice as many suspected suicides this year in jail compared to last year, and six times as many self-harm incidents.
Green Party corrections spokesperson David Clendon says the spike shows we're not getting on top of the problem.
"We're not managing our prisons well, we're not treating people appropriately, we're not anticipating problems with individuals."
Mr Clendon says it's not right for Judith Collins to say the figures just reflect society.
"I don't think it's sufficient to say, 'Well that's simply how things are'," he says. "I think that's just giving the game away altogether.
"I think we have to actively engage and think very hard about what's wrong with our practice that is causing these incidents of self-harm and suicide."
Mr Clendon says prison doesn't need to be a stressful environment and prisons need to be made safer, not jam-packed with more people.