Police have backed the use of electronic ankle bracelets, despite an escape rate of 13 per cent since their introduction six years ago.
There have been 1839 defendants subject to electronic monitoring since 2006/7, with 255 reported incidents of defendants absconding.
Electronic monitoring was introduced in 2006 as a cost-effective way of reducing the number of people serving time in prison.
If approved for electronic monitoring, a defendant would be fitted with an anklet which relays a signal to a control centre.
If a person goes beyond the monitored vicinity of the unit for an unauthorised reason an alarm is raised with police.
Inspector Mike Johnson, Police Prosecutions Service operations manager, said the police took "very seriously anyone absconding or breaching bail conditions and not complying with court orders - and take appropriate action in response".
The current monitoring contract expires in March 2013, and this would be the subject of a review.
Police declined to give details of the cost of each unit, as this could affect commercial negotiations over their procurement.
Police said $1,620,000 had been spent on the monitoring equipment between September 2006 and the end of October 2012.
Mr Johnson said the anklets were physically difficult to remove, and were designed to alert the monitoring company if they were tampered with, "so police do not consider the design or security of the technology to be an issue".
"However, defendants may attempt to abscond with the anklet still attached, which then alerts the monitoring company, who will advise police."
• $1.6m spent on system
• 1839 uses of electronic monitors
255 escape reports