The chairman of a Taiwan-based company suspected of buying recycled waste oil and mixing it with lard oil for sale to unsuspecting customers was reportedly detained Saturday on suspicion of fraud. Officials said Yeh Wen-hsiang was a flight risk, plus they said they were concerned he might destroy evidence or collude with other suspects.

Chang Guann Co. allegedly purchased 243 tons of tainted oil from an unlicensed factory and mixed it with other oil and sold it to customers across Taiwan. The company has been fined $1.67 million for selling poor-quality lard oil not meant for human consumption. At a press conference Sept. 11, Yeh Wen-hsiang got down on his knees and apologized to the public and also drank a cup of his company’s oil in order to show that it was safe. Taiwan’s prime minister, Jiang Yi-huah, has also apologized to the public and promised that oversight of food safety would be enhanced. Taiwanese health officials were said to be testing the gutter oil for heavy metals and warned that heating it to high temperatures might produce carcinogens. Tons of popular products, including seasonal mooncakes, pineapple cakes, breads, instant noodles, steamed buns and dumplings have been recalled since the “gutter oil” scandal recently came to light. The sale of Taiwanese products was also halted in nearby Hong Kong because of the problem. However, Taiwanese health officials indicated that Globalway, a Hong Kong-based trading company, may have supplied the lard oil, which is made from pork fat but is meant to be used for animal feed or industrial applications. Island officials have since banned importation of the lard oil from Hong Kong and promised to start inspecting all cooking oil. Additional products such as snacks and cookies were being pulled from store shelves across Taiwan on Friday on the order of health authorities, and a Japanese-owned fast-food chain doing business there announced Saturday that it was suspending the sale of five different hamburger products because of the tainted oil problem.