In February, five Form two girls from Sheung Shui Government Secondary School were taken to hospital after they allegedly took drugs during lunch hour.
Two teenagers, aged 16 and 18, were later arrested for selling the drugs to the girls. The case caused an outcry about the sale and use of drugs in schools.
Young Post talked to a former school drug dealer and addict about his battle with drugs.
Kenny, now 21, has left his former life behind and is drug free and working with Operation Dawn to help other people quit.
He says he feels sorry for what he put his family through.
'Many young people cannot tell right from wrong. Many of them take drugs simply because their friends are doing it.
'I used to be like that, but now I have learned to make the right choice in life.'
Kenny says triad members often get teenagers started by offering them free samples.
'There's no good reason to take them, and it is up to the students to make the right decision and say no,' he says.
Kenny first tried ketamine when he was 13, and says he was immediately hooked, using drugs at least once a week. But, because buying drugs was a financial burden, he decided to be a dealer.
'At that time I was a triad member,' he says, 'and getting hold of stock was not a problem. I sold drugs mainly to people in my school and business was not bad. But I didn't make much money because I was taking the drugs too.'
After finishing Form Three, he took up a job as a warehouse assistant and stopped dealing drugs. But he soon quit the job and went back to the drug trade.
'Working at a warehouse was boring, so I decided to deal drugs for a living. My parents knew what I was doing and even saw me bringing bags of drugs home. They were heart broken but they did not know what to do.'
Kenny says drug abuse made him violent and irrational, causing him to pick fights with people and get into trouble with the police.
'At the age of 19, I was convicted for assault and was sentenced to jail but I pleaded my case with the judge, saying I was a drug addict and wanted to quit.'
In fact, he says, he had no intention of quitting and made the plea simply to avoid doing time. But at Dawn Island Drug Treatment and Rehabilitation Centre something happened - the daily prayers and Bible readings and visits from his family began to transform him.
After a year on Dawn Island, Kenny was ready to re-enter society but Operation Dawn offered him a post.
'I decided to stay because I [wanted] to make the right choice in life and not feel lost again. I might have a relapse if I was on my own,' he says.