Now he works for White Ribbon raising awareness of domestic violence.
Mr Tamati's stop off in Hawke's Bay is for the prison's annual Chasing Sun Rays even - a walk and run-a-thon to raise funds for Victim Support.
Currently, 3686 people are incarcerated around the country for violent offences - that is nearly 40 percent of the prison population.
As part of the event, prisoners, staff and community stakeholders make a gold coin donation and complete a track around the prison field.
It gives inmates an opportunity to speak with people from community family violence providers.
One inmate from Te Whare Tirohanga Māori says he is unsure where to turn for help.
"I've been there, I've done that and that's not the person I want to be, it's very motivational for me."
Another inmate says, "It really hit home for me, a couple of the things [Vic Tamati] was talking about cause we can relate to it."
Over the last three years more than $2,000 has been raised for Victim Support and Women's Refuge through the event.
White Ribbon day is just one way of encouraging those who need it to seek help.
Made with funding from