Hundreds of tonnes of beef from a mad cow disease-hit area of Brazil were found on the Chinese market before the country lifted its import ban in July.

After an 11-month investigation and manhunt, police in east China's Jiangsu Province nabbed 27 people for their involvement in the sale of beef smuggled from Brazil, with some 300 tonnes of the beef confiscated, the provincial public security bureau told Xinhua on Tuesday.

According to the bureau, police clamped down on eight illegal beef-trafficking chains and caught four beef suppliers allegedly engaged in illegal deals, thanks to a tip-off earlier this year in Guanyun County of Lianyungang City.

Dai Leyu, deputy head of the county's public security bureau, said the beef suppliers adopted a secret sales mechanism: selling local beef in markets while hiding most of the cheap meat from Brazil in remote frozen warehouses. If any butcher needed smuggled meat, the deals were done via bank cards, with the vendors offering home delivery services.

Police are continuing to investigate other sales networks in the case, Dai said.

One of the biggest meat-consuming countries in the world, China placed a ban on beef from Brazil due to an outbreak of mad cow disease in late 2012.

"Although tests show the smuggled beef is not contaminated with foot-and-mouth disease or mad cow disease, and China lifted the ban in July, consumers wonder, how can the risky beef be smuggled into the market?" Jiuduanqiao asked on China's Twitter-like Sina Weibo.

The smuggled beef attracted many Chinese consumers because of its low price. Local raw beef costs 60 yuan (9.8 U.S. dollars) to 80 yuan per kilogram, while Brazilian beef only costs half of the price of local beef.