Police in China’s southern province of Guangdong have seized $12.3 million of potentially hazardous frozen meat including some reportedly soaked in bleach.

Sixteen suspects were detained in the raid late last week, say local police, who uncovered 1,000 tons meat and offal — chiefly from the U.S., Brazil and Thailand — on a vessel near Dangan Island by the city of Shenzhen.

“A criminal gang that used to smuggle frozen meat products, along with marine smuggling channel in Guangdong waters, were busted in the crackdown,” said a police statement, reports the state-backed China Daily newspaper.

Police said some of the haul — including beef cuts, tripe, tongue and chicken wings — had been soaked in bleach in order to clean the meat and increase its weight. A kilogram of beef weighs more than 1.5 kg after soaking in highly toxic bleach, said police, warning that the doctored meat would have “seriously harmed people’s health.”