Hong Kong's food authorities have basically agreed to resume imports of freshwater fish from south China's Guangdong Province before Christmas, after details on the import quality guarantee were settled with the Guangdong quarantine department in Guangzhou.

Malachite green, a cancer-causing chemical, was found in freshwater fish exported from China's mainland to HK in August last year. The chemical had not been put as banned substance in HK before, according to Hong Kong's Health, Welfare and Food Bureau.

The bureau reached an agreement with the Guangdong Entry-Exit Inspection and Quarantine Bureau on the safety requirements of freshwater fish for supply to Hong Kong on Monday. HK agreed to resume normal fish imports from Guangdong on Dec. 22, if preparations by the two sides are done on schedule.

Hong Kong only allowed direct fish imports from several qualified mainland fish farms, after the harmful substances were found.

The bureau pledged to give equal treatment to fish products from China's mainland as those from HK and Southeast Asian countries.

Meanwhile, the Guangdong side vowed to see to that all aquatic product exports to HK shall be tagged with proper certificates of origin.

Malachite green is used to treat fungal infections at fish farms and has been banned in the Chinese mainland since 2002.