Positive drugs tests in prisons are at the lowest they have ever been, with no positive tests in the past 10 months at Auckland Women's Prison, the Corrections Department says.
Random urine tests were being conducted at all of New Zealand's 20 prisons every week, with about 80 tests being carried out each week.
There was no way to cheat the tests, with the prisoners selected randomly by a computer programme at Corrections' national office in Wellington, tests supervised by staff and samples sent to an external laboratory for analysis.
There had been no positive tests at Auckland Region Women's Corrections Facility over the past 10 months, proving that the prison's perimeters were being kept secure, prison manager Agnes Robertson said.
The security at the prison, which opened in 2006, was sophisticated compared to other prisons, with only one point of entry, metal detectors, scanners, drug dogs and closed circuit television cameras.
Staff were also responsible for keeping drugs out of the hands of women who had histories of drug use or drug-related offending.
"Absolutely everything", down to staff possessions and courier drivers' vans, was searched, and prisoners' phone calls were monitored, Ms Robertson said.
NZPA