Shanghai police recently cracked a Japanese beef smuggling network in a joint effort with Shanghai Customs after four months' investigation.

The network had smuggled 97 tons of beef into China, most of which was sold in Shanghai. The amount of money involved is estimated at over 30 million yuan ($4.8 million), said Zhou Shizheng of the Food and Drugs Crime Division of the Shanghai Public Security Bureau.

According to the police, Japanese Toukura Company smuggled Japanese beef into Yunnan province from Laos in fruit containers. They then shipped it to Shanghai disguised as ham, before selling it to high-end Japanese restaurants in the city.

In a campaign initiated on March 25, about 13 tons of smuggled beef was confiscated and 17 suspects arrested. The price of the beef, which was 200 to 400 yuan per kilo in Japan, doubled in Shanghai, said Zhou.

China has banned the import of Japanese beef since 2001 out of concern for mad cow disease and foot and mouth disease. All Japanese beef sold in China is either illegal or fake, said Li Qing of Shanghai Customs.