As many as 8,000 smugglers carrying small numbers of products from Hong Kong and Macao go through Shenzhen and Zhuhai customs in South China's Guangdong province every day, according to the latest figures from the General Administration of Customs.

Such smugglers, who are called shuike, are usually hired by smuggling gangs and frequently go back and forth between the two sides carrying products to evade custom duties. Some of them cross the border 50 times a day, according to the administration.

They usually carry small products with high value or brand goods in short supply, such as digital cameras, laptops, jewelry, make-up, nutritious supplements and medical supplies, foreign wines and currency, and obscene and pirated DVDs, Tao Yong, a press officer from the administration, told China Daily on Thursday.

"Shuike smuggling has become a serious problem, which has undermined national foreign trade management, caused great losses to State tax incomes, and led to unfair competition in the market," he said.

"In addition, the smuggled drugs, food and daily commodities do not undergo border quarantine inspections, and this may pose threats to public health."

Although such shuike carry only a small number of products, they are usually controlled by professional smuggling gangs and work as "moving ants". The method can be considered organized smuggling, Tao said.

In September the General Administration of Customs launched a special campaign to combat such shuike at Shenzhen and Gongbei customs.

By the end of October, 939 cases involving shuike had been cracked, with about 50 million yuan ($7.5 million) worth of illegal profits seized, according to the administration.

Tao said such shuike smuggling chains usually have several links: product suppliers, a shuike group boss, individual shuike and product receivers inside the border.

The smuggling methods are highly secretive, Tao said. "They usually conceal the smuggled goods on their bodies and in their luggage. Sometimes shuike bosses even hire the disabled, the elderly, or minors to help with the smuggling."

Tao cited one example cracked by Shenzhen customs in September, in which 33 shuike were detained and 20,000 carats of diamonds, worth 166 million yuan, were seized.

Zhao Chenmin, a Beijing-based lawyer who specializes in smuggling cases, said that because shuike involves small amounts of money in individual cases, the smugglers are able to exploit loopholes in the law.

"People smuggling goods, such as electronic products and cosmetics, with a value less than 50,000 yuan, are subject only to administrative punishments instead of being considered criminals," said Wu Ming'an, law professor at China University of Political Science and Law.

"Administrative penalties, such as fining wrongdoers, are imposed by customs and are usually very light," he said.

Wu said the General Administration of Customs should improve its inspection skills and distinguish between smugglers and common people who also carry products for their own use.