The Corrections Department says it has significantly improved standards for monitoring prisoners on parole.
Last year, the Auditor-General issued a report harshly criticising the department's failure to follow processes in the management of high-risk prisoners.
The report followed the killing of a Lower Hutt man in January 2007 by Graham Burton, a convicted killer who had been released on parole.
Burton served 14 years in prison for murder after a fatal stabbing outside a Wellington nightclub in 1992.
Two years ago, only 56% of cases were being handled properly. Latest figures show that has now risen to 96%.
The department says standards have been made clearer and there is no confusion as to what the bottom line is or what the mandatory elements of managing an offender are.