Chiu tendered his formal resignation following the completion of an investigation that saw eight suspects indicted on charges of fraud and breaches of food safety regulations.
In his resignation statement, Chiu apologised to the Taiwanese public for a scandal that saw thousands of consumers demand refunds from bakeries across the country after food inspection authorities discovered that hundreds of tonnes of lard h Jiang Yi-huah ad been manufactured from so-called gutter oil—cooking oil that had been recycled from kitchen waste and grease from leather processing plants.
Chiu had previously taken responsibility for the scandal and had repeatedly offered to stand down, though the island’s administrative head, Jiang Yi-huah, waited until the investigation was over before accepting his resignation.
In early September, Taiwanese police uncovered an illegal ring who they claimed had manufactured the gutter oil at around a dozen unlicensed sites in Kaohsiung and Pingtung, before selling it on for use by some 1,020 retail businesses.
Those charged included Kuo Lieh-cheng, owner of the illegal factory which made the oil, and Yeh Wen-hsiang, chairman of Chang Guann, which bought Kuo's product and processed it into lard.
Yeh has been detained since September 13, after investigators discovered his company had purchased 243 tonnes of tainted oil collected from cookers, fryers, and grease traps, as well as recycled grease from leather processing plants.
Among the other businesses, Wei Chuan, Vedan, Want Want and Master Kong were identified as having used the oil.
Massive recalls of products ranging from cakes to instant noodles have taken place over the last month, making this Taiwan's worst food scandal in recent years.
At the time, Taiwanese Premier Jiang Yi-huah ordered all food and oil products produced by 235 local companies to be removed from shelves after tests showed they had all used gutter oil bought from the ring.
“Premier Jiang was pained to find such a serious irregularity and ordered that relevant authorities and agencies continue their inquiries into the case and mete out severe penalties against those involved in the scandal,” Cabinet spokesman Sun Li-jen said as the scandal broke.
This is the second food-safety scandal to hit Taiwan in less than a year. Last December, a factory owner on the island was sentenced to 16 years in prison for selling olive oil that had been adulterated with cheap cottonseed oil and a banned colouring agent, resulting in mass product recalls.