Two of six eel samples taken in a recent Food Safety Centre operation were found to contain malachite green, its Principal Medical Officer (Risk Management) Dr Tina Mok says.

The centre inspected seven premises, including restaurants and suppliers suspected of selling eel products from dubious sources, and took six samples for chemical tests.

The two samples concerned, containing 16,000 parts per billion and 2.5 ppb of malachite green, were taken from a Japanese restaurant and a supplier in Yuen Long.

The malachite green levels detected would not pose any adverse health effects, she said.

The centre seized all remaining stock of eel products, about 400 kilograms, found in the two premises.

Investigations are underway. The centre will consider prosecuting the restaurant operator and the supplier.