"We're talking about some of the most dangerous, sometimes most violent, most difficult people in our society and that's why they're behind bars.
"We can use technology, we can use devices like this to role model what is acceptable behaviour so when the camera is on them, they're less likely to misbehave."
He said prison guards and unions were welcoming the idea.
It was about making prisons safer for guards and prisoners alike, Mr Lotu-Iiga said.
The trials in New Zealand prisons had seen a 15 to 20 per cent reduction in disruptive incidents.
The cost of the cameras was "commercially sensitive" but within the department's budget, he said.
"I think it's one of those things that the unions and the department can agree on.
"We have seen serious assaults come down over the last few years but there are a lot of other minor assaults and tensions and I think these sorts of devices, technologies, have got to be used in our prisons to make them better places to work and better places to live."