Hong Kong  - A voluntary drug testing scheme involving Hong Kong secondary school students will go ahead in December despite a growing row over privacy concerns, a media report said Wednesday.

The pilot scheme will involve 23 schools in the Tai Po district of the city, but experts have raised doubts about the legality of the plan, the South China Morning Post newspaper said.

Under the government proposal, parental consent will be required to collect urine samples from children under 18, while for those aged over 18 both the parents and the student need to give their approval.

Permanent secretary for education Raymond Wong Hung-chiu said the government had taken legal advice over the privacy issue and indicated the "implementation details can be fine-tuned in coming months."

But privacy commissioner Roderick Woo Bun challenged the proposal and told Education Minister Michael Suen Ming-yeung that under privacy laws guardians had no authority to give consent on behalf of a minor.

University of Hong Kong professor John Bacon-Shone, added: "The students should fully know in advance what is going to happen in the drug tests, who is going to see the test results and how long the results are to be kept."

He said details about the confidentiality and storage of data had yet to be revealed.

In response Wong said: "This is a voluntary scheme, which parents and students will be fully informed about before joining the programme. I believe the chance of a legal challenge over this matter is very low."

The drug testing scheme was proposed in response to a series of incidents involving teenagers who were found to be in possession of drugs or under the influence of drugs while at school. (dpa)