China's top market watchdog announced on Thursday that nearly 25 percent of the country's chilli pepper products have been found to be contaminated with cancer-causing Red Sudan dyes.

According to the General Administration of Quality Supervision, Inspection and Quarantine, the result came from a quality overhaul of 137 chilli products in eight provinces and cities including Sichuan, Chongqing, Hunan, and Hubei.

The administration found that 34 of the 57 loose chilli products in 23 rural markets contained Sudan dyes.

However, the quality checks of the packed chilli products sold in supermarkets and shopping malls in cities yielded better results. Only one of the 80 chillis tested was found to contain Red Sudan dye IV.

The administration ordered producers to carry out testing for Sudan dyes and to provide Sudan dye-free certificates.

Red Sudan dyes are used in the leather and fabric industries. The International Agency for Research on Cancer, part of the World Health Organization, classified Sudan dyes as Group 3 genotoxic carcinogens.

In 2005, China's Ministry of Agriculture reiterated the ban on production, sale and use of Sudan dyes in food, after it was found in some brands of pepper sauce, chili oil and fast food giant KFC's New Orleans roast chicken wings.

In a separate food safety scare, red-yolk duck eggs contaminated with Sudan dyes were reported in many parts of China in November last year.

(Xinhua News Agency January 19, 2007)