Food Safety Centre Controller Dr Mak Sin-ping says tests on 20 seawater fish samples have shown they are free of malachite green, but low levels of nitrofurans have been detected in three samples.

They were a pompano from a PARKnSHOP in Tai Kok Tsui, and a tiger grouper and a flowery grouper from a Kwun Tong wholesaler. Both outlets have stopped selling these fish.

Dr Mak said today the level of nitrofurans found in the three samples ranges from 0.0026 to 0.47 parts per million. Normal consumption of these fish will not hurt health, and people should maintain a balanced diet.

The centre is still tracing the source of the tainted fish. According to the wholesaler, both fish came from Southeast Asian countries.

Dr Mak said the Government is assessing the live fish and seafood monitoring system. Noting seawater fish can come from different countries, she said the feasibility of establishing a registration system for seawater fish farms has to be explored.

On freshwater fish, Dr Mak said Hong Kong has been maintaining close ties with Mainland authorities. She said people's confidence in freshwater fish will resume gradually as recent test results have showed no traces of malachite green and nitrofurans.