Corrections Minister Paul Swain has asked for a report on career criminal Sean Broderick's breach of home detention last week.
Broderick, 37, has not been seen since he walked out of a Hamilton house last Saturday and was picked up by two men in a white ute.
His detention anklet
was attached to his leg.
United Future law and order spokesman Marc Alexander said the case showed the "sheer stupidity" of the home detention system.
"How does a thug get home detention? It's a very simple question, but there are judges and justice officials who need to start answering for this rubbish.
"There is only one place for violent criminals and those who carry a genuine threat of violence, and that is behind bars," he said.
Mr Swain told National Radio he had asked officials for answers to several questions about the Broderick case.
It was fair to ask why Broderick had been sentenced to home detention.
He wanted to know what the Corrections Department had recommended to the Parole Board regarding Broderick.
He also wanted to know if the time taken for the alarm to be raised after Broderick escaped was within acceptable limits set by an agreement with the security firm that monitored any breach.
Community probation service spokeswoman Heather Mackie said this week that ankle bracelets acted as alarms.
"The system works at the moment as an alarm system. It means we know if someone is in a particular place that they are confined to ... and it alarms if they leave that place."
Ms Mackie said the service and police were informed quickly when the alarm was activated and started looking for Broderick.
The service was about to test a global positioning system, which might offer a "better level of security", she said.
Mr Swain said he wanted to know if a GPS system would have helped in the Broderick case.
In November, 43 people were on home detention in the Waikato, but Broderick is the only one known to have broken his sentence.
He was supposedly seen doing banking in Hamilton last Friday - the same day police warned he was a dangerous serial offender who should not be approached.
- NZPA
