Guangzhou Customs have cracked China's biggest white sugar smuggling case in recent years, in seizing more than 1,600 metric tons of the commodity from a vessel in the Pearl River estuary.

Tan Junquan, deputy director of Guangzhou Customs' anti-smuggling bureau, said the white sugar, from Thailand, was valued at more than 10 million yuan ($1.56 million).

"Ten suspected smugglers were detained in the operation," Tan told a news conference in Guangzhou, capital of Guangdong province, on Thursday.

Zhu Yi, deputy director of smuggling control for Dachan Customs, said the big price gap between the domestic and global markets had encouraged smuggling in recent years.

The price of white sugar on the global market has hit a nine-year low of 2,000 to 3,000 yuan a ton, but it traded for about 5,000 yuan a ton in the Chinese mainland.

A task force was established after big data analysis identified a vessel suspected of smuggling white sugar from Thailand into Guangdong last month, Zhu said.

After days of investigation, an operation was launched to seize the white sugar, carried on a vessel near Longxue Island, at about 2 am on May 18.

In another operation, early last month, customs officers detained four suspects after seizing more than 3 million yuan in smuggled secondhand electronics, including mobile phones, iPads, cameras and video cameras.

Guangzhou Customs investigated 1,533 smuggling cases, valued at more than 1.58 billion yuan, in the first five months of this year.

In addition to electronic products and white sugar, they seized 2,370 tons of frozen products, 3,746 tons of finished oil, 4,608 bottles of foreign wine and 32 tons of pistachio.

Tan said efforts to fight smuggling in the Pearl River estuary would be redoubled in the months ahead.