A remorseful father made an emotional confession to failing his son, at a 'Whare' Graduation ceremony at Ngawha prison.

The ceremony was for the young graduates of a programme aimed at reducing their potential to re-offend.

The father said he'd had a "who cares?" attitude.

''People were walking in and out of the house with stolen stuff, stuff that wasn't ours," he said.

"We didn't realise the effect we were having on him at that stage. We were teaching him not to value stuff, and stuff like 'Who cares about respect [for] other people?' What we instilled in our boy was if they're not [our family] then f*** them.

He said there were none of these programmes to stop reoffending back then.

"Then we started having other kids, a daughter, another son, another daughter, another daughter.

"Then one day we realised what we were doing was not right for them and their children, so I decided, me and my missus, that we needed to change our ways,'' the repentant father said.

''What we were doing was affecting our kids, we watched other families around us; the teenagers were doing drugs and [killing] themselves because they had no mechanisms to help themselves and how to deal with life.

"The way I see it, it's the parents' fault with all these young ones going off the rails. They need to be the ones supporting the young ones going through life ...

"So we decided to change our parenting. Unfortunately, it was too late for my oldest boy. We had already instilled in him the bad ways - we instilled 16 years of it into him - but it was not too late for the others.''

He said when they did change their parenting, the other children were okay.

''But this guy, my son, had a hard job of adjusting to the new regime.

"I achieved my goals but I forgot about my son ... I left him to his own devices.

"Because I did that to my son it is only right that I be standing here in front of you to tautoko, to support him,'' the man said.

"My missus gave me a list of things that she wanted me to do.

"Top of the list was for me to get a job, and get off the WINZ [benefit]. I used to worry whether the brothers would respect me after I changed my ways and got a job or the new way I am.

"Now I don't care about that. At the end of the day I am here today to support my son, because we brought him up like that, and I love my son.

"What the facilitators have done here in the way of aroha and empathy has been amazing.

"His grandparents also instilled that in him when I was in jail. I never instilled anything like that in him."