TAIPEI: Taiwanese health authorities said Friday they were investigating more than 200 companies which allegedly used recycled cooking oils obtained from restaurants in their products, in the latest food safety scandal to hit the island. Police and prosecutors also said two underground factories were busted on suspicion of selling processed waste oils — collected from cookers, fryers and grease traps — including to one that supplied leading food oil manufacturer Chang Guann Co.

Another factory allegedly recycled grease from leather processing plants for oils used in animal feeds.

Officials said that Chang Guann then sold the oils on to at least 235 companies, including a number of leading brands, as lard-based cooking oils. The investigation was launched after police received tip-offs that waste oils were being collected from restaurants and food stands, processed and then re-sold.

Health authorities are investigating all the firms that may have sold or used the tainted material in their products. Chang Guann has apologized but said it was unaware that the oils were recycled so it too was a victim in the case.