The Government is looking at changing the type of electronic monitoring bracelet used, following a spate of escapes by people cutting them off.
Earlier this month, child rapist Daniel Livingstone was on the run for a day and a half in the Hutt Valley after he removed his bracelet and fled police. Two weeks later, a Southland man repeated the exercise.
Corrections Minister Sam Lotu-Iiga would not be interviewed, but in a statement he said he was concerned by the number of offenders cutting off their anklets, and had asked officials to investigate whether there were stronger models that could be used.
But a patron of the Howard League for Penal Reform, Nigel Hampton QC, said the problem was not with the electronic monitoring system itself, nor the devices, but with the contractors tasked with keeping tabs on those being monitored.
"A delay, or not ready enough response, by the contractors who are being used to monitor the bracelets, and then a fall down between them... responding, to notify the police."
Mr Hampton questioned why security guards, not police, were sent to check on violent offenders who cut off their bracelets.
"It's probably better that it's straight into the hands of police officers.
"Police officers will say we've already got enough to do, but they're the people with the ability to immediately take steps, to enforce, to arrest."
Criminologist John Pratt said cutting off monitoring bracelets was not a problem that had cropped up in any great numbers until recently and there is a copycat element to the recent spate.
Professor Pratt, of Victoria University's Institute of Criminology, told Morning Report the solution isn't necessarily strengthening the bracelets.
"I don't think they are that easy to remove - it's not like just taking off a watch or something like that - but clearly a small group of people have realised it's not impossible to take them off."
Kim Workman, strategic advisor for Rethinking Crime and Punishment, said the number of people breaching electronic monitoring conditions had always been high.
He said Corrections was intent on expanding the system, despite international evidence showing it did not actually work very well to stop reoffending.
While monitoring could work well for some offenders, Mr Workman said, most wanted to serve their time and move on and monitoring made them feel like they were still being punished.
"They set the criteria far too high, so you really can't walk around the street. If you're prohibited from going to a park, [then] it's very difficult if you're going out to do your shopping and there's a park right next to the shopping mall."