Wang Peng uses two mobile phones and two computers and has eight online identities in more than 20 different chat groups. He's a police officer pretending to be a drug user, and he needs to put on a convincing performance.

Wang, which is not his real name, is the captain of the eight-member anti-drug team in the Tianjin Public Security Bureau.

As drug dealing is increasingly organized online in China, police are targeting chat groups and mobile social applications, which have been the main battlefield for drug control.

A major part of Wang's work is pretending to be a drug user and spending hours chatting with other users and dealers via mobile apps and online forums.

"For each chat group, I have a different name, background information and photo. It is crucial to keep all the details consistent in each group when constantly switching among them, otherwise they will doubt me," said the captain of the No 5 drugs crew.

"Once they don't trust you, they will immediately withdraw from the group. It requires no less caution if you are online chatting than capturing them in real life."

However, the drug dealers have also grown more cautious. Once, Wang and his colleagues were asked to show how they use drugs via video chat before getting admitted to a chat group.

To win their trust, they used ground rock candy as pretend methamphetamine, or ice. They also boiled water to make it bubble. The biggest challenge was how to make it smoke.

"It was really a dramatic performance," said the 36-year-old, who stayed in the group for a month and finally seized a kilogram of drugs from the dealer.

Tianjin-based Morning Post contributed to this story.

(China Daily 06/27/2015 page4)