Customs officials in Shenzhen, Guangdong province, have stepped up efforts to block the smuggling of Apple's new iPhones.
The phones have been on the market in 10 countries and regions since Sept 19 but were excluded from the Chinese mainland.
As of Tuesday afternoon, Shenzhen officials had seized more than 200 iPhone 6 handsets smuggled from Hong Kong. Another 1,600 identified as self-use goods had import duties imposed on them or were returned to Hong Kong, customs data showed.
"We target smugglers who illegally carry the phones from Hong Kong to Shenzhen for profit. Individuals who bought phones for their own use just need to pay the duty and will not be punished," said a press official, surnamed Li, at the Luohu checkpoint.
Apple's iPhones are on a list of 20 items on which duty must be paid. The duty is about 10 per cent, Li said.
About half of the new iPhones were caught at the checkpoint, one of the country's busiest land checkpoints.
On Sept 20, customs officials at Luohu saw a man acting suspiciously. He seemed to want to keep his distance from inspectors, who eventually discovered eight iPhones hidden inside his underpants.
Two days later, two men were caught carrying three iPhones inside their underpants in a joint effort by Shenzhen and Hong Kong customs authorities.
"We will remain on high alert, because the smugglers will invent ways to illegally bring in new iPhones," Li said.
At the Huaqiang North Electronic Market in Shenzhen, one of the biggest grey markets for Apple and other electronic products in Guangdong, the cost of a 16 gigabyte iPhone 6 Plus varies from 11,000 to 15,000 yuan ($1,790 to $2,440). The price at an Apple store is about HK$6,390 ($830).
The price for a regular iPhone 6 is lower－about 7,050 yuan－but still above the official price in Hong Kong of HK$5,588.
"The price of an iPhone 6 is down by 2,000 yuan compared with three days ago," one seller said, "So I suggest if you have one and want to sell it, you do so as soon as possible, while you can still earn about 3,000 yuan."
At Zhongguancun in Beijing, one of the largest electronic markets in North China, the iPhone 6 Plus sold at no less than 16,500 yuan on Monday, Beijing Evening News reported.