Government ministers initially rejected electronic bail but it was introduced as a way of reducing the number of remand prisoners held in custody, National MP Simon Power said yesterday.
Mr Power, National's justice and corrections spokesman, released documents obtained under the Official Information Act, showing electronic monitoring was first considered by the Cabinet in 2000.
Since September last year courts have had the option of electronic monitoring as a bail condition for defendants remanded in custody, and 18 have been granted it.
It has been disclosed that one man freed from custody under the scheme was now facing charges including attempted murder, wounding with intent to cause grievous bodily harm and aggravated assault.
The documents show that former Justice Minister Phil Goff recommended in 2005 against introducing electronic bail, but further consideration was given to the scheme and the Government approved it.
A Ministry of Justice report in October 2005 said: "If the primary purpose of EM (electronic monitoring) is to reduce inmate numbers, eligibility must be targeted to those who would otherwise be remanded in custody.
"However, defendants remanded in custody are more likely to have characteristics or criminal histories that would make them unsuitable for release on bail with EM."
Mr Power said the Government was not giving sufficient priority to public safety.
"The scheme is a dangerous experiment that needs to be overhauled immediately," he said.
"It should be stopped immediately for all except low-level, non-violent accused."
The police say it is up to judges to decide who gets bail, and they exercise authority under the terms of the Bail Act.
"They release on bail where they are satisfied that the defendant does not pose an undue risk to the community," electronic bail manager Lindsay Talbot said.
Government duty minister Rick Barker said the scheme gave judges more options.
"Figures show that of those who are remanded in custody awaiting trial, 50 per cent of them are subsequently found to be not guilty," he said.
"So you are dealing with people who at this stage are innocent but charged, and it is a serious decision to take someone's freedom off them pending a decision."