Delicate detection: Government Laboratory Acting Senior Chemist Dr Wong Wing-cheong briefs Commissioner for Narcotics Sally Wong on new hair drug-testing technology. Ms Wong is also shown confirmatory test procedures in the Tai Po school drug-testing trial.

The Government Laboratory has developed a drug-testing method using hair samples that will be used to conduct a small-scale pilot scheme, possibly next year.

The laboratory's Acting Senior Chemist Dr Wong Wing-cheong briefed the Commissioner for Narcotics Sally Wong on the new technology today.

Each test using the new method will need up to 100mg of hair, or 20 to 60 pieces of hair 4cm long, and will take eight hours to check whether the tested person has taken drugs in recent months.

The method is considered faster, more accurate, safer and less offensive to the tested person. The sample storage is also easier.