A new kit that can be used to test children for drugs has been criticised by parents and welfare organisations.
The HairConfirm kit costing $225 allows parents to cut between 90 and 120 strands of hair about 4cm to 4.5cm long to determine drug use in the past 90 days, The Dominion Post reported.
The parents then send the strands to a lab where they are tested for seven illegal drugs: marijuana, cocaine, opiates such as codeine and morphine, amphetamine, methamphetamine, ecstasy and PCP (Phencyclidine).
The results of the tests are made available to parents via a secure website within two days of the lab receiving the sample.
Children's Commissioner John Angus said parents should be concerned about possible drug use by their children.
However, it would be more appropriate for them to have an honest relationship with their kids.
"Surreptitious drug testing would not help."
Drug Foundation executive director Ross Bell said the people who sold the tests did not provide any support.
Spokesman for Drug Detection Agency, which sells the kits, Nick McLeay, said there were guidelines for parents and recommended "a clear and open discussion with parents and the child".
Christine Davey, from Auckland, who has not seen her drug-addicted son for two years, said she did not support the hair tests.
She said she would like to see more support and stronger partnerships between communities and local police.
Council for Civil Liberties spokesman Michael Bott said the tests would be counter-productive and might create a climate of suspicion.
Health Ministry figures from 2007 showed that one in five 13 to 17-year-olds had used cannabis in the previous 12 months.
The first batch of "cheat-proof" kits have been available in New Zealand this month.
