About 1,700 kg of drugs have been seized by the Shenzhen Customs in the past three years in 109 narcotics cases, according to its latest statistics. About 160 kg drugs are waiting to be destroyed.

The Customs enforcement teams also launched an operation against 14 cross-border smuggling gangs and caught 143 suspects from 17 countries and regions.

Wang Zhi, deputy commissioner of Shenzhen Customs and director general of its anti-smuggling division, attributed the success of the operation to the closer international co-operation.

He said it's getting more difficult to find hidden drugs as traffickers are using ingenious ways to smuggle them, including concealing them in a pregnant woman's stomach, in a modified bra, in the interlayer of a trunk and in the car exhaust.

Apart from the traditional manual inspection and sniffer dogs, the Customs department is analyzing big data taken from various sources, such as its own database, immigration department, airport cargo warehouse receipts, postal parcel records and DNA drug testing.

"Analysis and screening helps the officials better detect the objects with higher possibility of finding drugs," said Wang.

Based on big data analysis, the Customs officials zeroed in on an express delivery destined from Hong Kong to Taiwan, and then to Shenzhen, with Australia being its final destination.

On April 16, the officials discovered 3,685g of ice, a drug, in the delivery, which was declared as bags and shoes. Two days later, another parcel was seized with 3,946g ice.