The government said that tests on samples of saltwater fish sold in Hong Kong’s markets had traced small amounts of the banned antibiotic nitrofuran. In small doses nitrofuran is used to treat illnesses such urinary infections, but larger doses are believed to be dangerous and potentially carcinogenic.

No cause for alarm
Dr. Mak Sin-ping, controller of the Centre for Food Safety, a government lab, said the chemical was found in minute concentrations in samples of pompano, tiger grouper and flowery grouper fish. "As the levels of nitrofurans detected in the fish samples were low, normal consumption should not pose any adverse health effects," Mak said in a statement. "There is no cause for undue alarm. "We would continue to monitor the situation closely to protect public health," she said.

The fish are believed to have been imported from China, the source of the vast majority of this city’s food. Supplies of freshwater fish from the mainland, which come under stricter import checks that saltwater fish, have been halted since samples were found with the cancer-causing industrial dye malachite green, a banned additive that is nonetheless found in some farm-fish feed.

Many scares in a few years
The latest fish scare follows many in the past couple of years that have prompted temporary import bans, mostly concerning the presence of malachite green. However, chicken eggs recently came under the spotlight after it was found the carcinogenic Red Sudan dye was being added to some mainland chickens’ feed to produce red egg yolks, seen as a delicacy in China.