Police of Shenzhen Customs seized 40 kilograms of cocaine in a container in May. [Photo provided to China Daily]

Intelligence plays a key role in drug-related cases, and experience, technology and special equipment can effectively and accurately combat such crimes, said a narcotics police officer in Guangdong province.

"Our first and foremost responsibility is to guard the country, but we also should maintain the order of legal trade. We can't check all of the containers and mail one-by-one, but we still need to ensure there are no drugs entering the country through customs, which puts a lot of pressure on us," said Dai Haifeng, 42, deputy head of the second investigation division of Anti-smuggling Bureau of Shenzhen Customs in Guangdong province.

The division currently has 20 police and has solved 902 drug smuggling cases over the past five years. On Tuesday, the division was honored by the National Narcotics Control Commission as one of the 100 organizations that have made prominent contributions to drug control in China since 2015.

According to Dai, more than 600,000 people cross the Shenzhen border on average each day, and more than 1 million parcels pass through the mail.

Solving a case cannot always bring the joy of success, but sadness sometimes. Dai recalled one colleague, surnamed Zhang who died at the age of 46 during a business trip to follow up a drug case in 2014.

"He won the first-class merit for his outstanding performance in solving a major drugmaking case, but he died before receiving an honor, which is really a pity. I think people who want to be a policeman have an admiration for heroism and devotion to family and country. The smallest supportive comments from the public could drive us to continue to fight the crimes," he said.

Dai grew up in a family of police officers, and his father and brothers are policemen. Though he had wanted to become a lawyer when he was in university, he was attracted by the work in customs.

"My family often worries about me, especially when I'm involved in a task. They'll stay up to wait for me to come back. Due to the confidentiality of daily work, I can't say much about work to them, only to ask them not to worry," Dai said.

"Drugs are like a cancer in human society, the drug addict and dealer are the cancer cells and continue to spread in society, dragging down people around them. It is the narcotics police's responsibility to stop the trend. We all have a vision of a drug-free world, and we wish that day would come sooner," he added.