Two correctional services officers told court they falsified urine samples for drug tests in 2009, even though, it emerged yesterday, a computerised system existed that kept track of the whole testing process.
Eastern Court is due to hand down its judgment on Thursday as to whether Tang Kwai-man and Leung Siu-wing acted under instructions when they swapped urine samples obtained from released inmates to suppress drug relapse figures.
The Correctional Services Department held a press tour of its urine test centre in Stanley Prison yesterday to hit back at what it said were inaccurate media reports on the court case.
Assistant commissioner Lam Kwok-leung said a computerised system was put into operation in 2008.
"We try our best to use all possible ways, like instruments, monitoring mechanisms and computers to minimise human involvement. Is there any way to completely rule out human contact? I think it is relatively difficult," he said.
Lam also said an officer was sent to monitor the sample collection process. He said the department would review if there was any need to have more officers to monitor the process after the court case, but ruled out using closed-circuit television.
Tang and Leung Siu-wing were in charge of supervising former inmates after they were discharged from the Hei Ling Chau Addiction Treatment Centre. They admitted failing to visit some ex-inmates, not being present when they produced urine samples and not recording that two admitted taking drugs. Leung said he provided urine for two former inmates himself.
Principal officer Choy Yu-tin said urine samples collected outside prisons from released inmates had to be returned to the testing centre within one working day. He said a bottle that could only be opened once was introduced in 2011 to prevent tampering during the collection process. But he did not know if the bottle was introduced because of the falsification case in 2009.
Urine samples, labelled with barcodes, are put into an optical analyser, yielding results in six to eight minutes. The machine immediately alerts senior officers if a sample tests positive.