China's state quality watchdog Tuesday announced that it had discovered the cancer-causing Sudan I in 88 kinds of food and food additives produced by 30 Chinese companies.

The State Administration for Quality Supervision, Inspection and Quarantine (AQSIQ) made public a list of the contaminated food and their producers on its website Tuesday.

The inspection was carried out in 18 provinces, autonomous regions and municipalities across the country on pepper sauce, pepper oil, spicy preserved food and spicy instant noodles, according to sources with the agency.

The 30 companies are mostly in south China's Guangdong province, east China's Jiangsu province and Shanghai municipality, said the source.

The red dye was first discovered early March in a pepper sauce made by a Heinz subsidiary, the Heinz Meiweiyuan Food Co. based in Guangzhou, capital of Guangdong.

The agency required local quality inspection departments to destroy the contaminated products right away.

The agency also instructed all the companies producing pepper products to strengthen self-checks of their product formulas, raw materials and final products.

AQSIQ will also carry out inspections in other provinces in China. It will intensify efforts to examine industrial companies that producing Sudan I and prevent it from entering the food industry, said the source.