HONG KONG has suspended the sale of over 30 species of freshwater fish from the mainland after its food safety authority detected a cancer-causing dye in a popular fish, the Oriental Morning Post reported yesterday (Nov 27).

The Hong Kong Food and Environmental Hygiene Department found small amounts of malachite green, an industry-use dye, in 11 samples of freshwater fish in an inspection of birds'eggs and fish on sale in the city, according to the Guangzhou-based Nanfang Daily.

The department has called on locals to temporarily stop eating mandarin fish, even though the carcinogen only appears to be present in small amounts.

Fish vendors are ordered to stop selling more than 30 species of fish, including the popular mandarin fish, accounting for one-third of the freshwater fish supply.

The department also banned sale of freshwater shrimps and crabs, with only the sale of carp allowed.

"The samples didn't contain harmful antibiotics, but we found 0.0022 to 2.3 milligrams of malachite green in every kilogram of the fish," said an official with the department.

Guangdong Institute of Food Science and Technology Vice President Chen Yongquan said small amounts of malachite green are not harmful, even though regulations prohibit it in seafood.

The Hong Kong authority conducted a second test Saturday and found one fish sample out of the 10 bought from a local wholesale market containing small amounts of the dye. The fish was reportedly imported from a legal fishery in Shunde, Guangdong Province.

Malachite green contamination was detected in a number of freshwater fish last year, including common carp and mandarin fish.

Insiders say domestic farmers previously used malachite green dye on fish to maintain their freshness and shiny appearance. However, the Ministry of Agriculture has stipulated that malachite green dye cannot be used in edible aquatic animals as large quantities can cause cancer.

Editor: Wing