Government officials are scrambling for the truth about the 18 freshwater fish farms designated by mainland authorities to supply Hong Kong markets after at least one was found not to exist. The Health, Welfare and Food Bureau said Shenzhen authorities had confirmed late on Tuesday that one of the farms chosen to supply fish free of the cancer-causing chemical malachite green was no longer farming fish. 'We will send officials to verify the situation of these fish farms very soon, about the quantity and types of their fish,' Secretary for Health, Welfare and Food York Chow Yat-ngok said. 'We hope we will very soon clarify the list and the actual situation.' Tommy Hui Hon-man, chairman of the Hong Kong, Kowloon and New Territories Freshwater Fish Association, said only one of the 18 farms was known to regularly supply Hong Kong. They were speaking after visits by newspapers, including the South China Morning Post, revealed that of the eight designated farms in Shenzhen, one had not operated for years, two did not seem to exist, a fourth was shut to make way for property development and operators of the remaining four knew nothing of the list. The central and Hong Kong governments have said a system of accredited exporters, who will certify their fish are free of noxious substances including the fungicide malachite green, is being put in place after tests in Hong Kong found malachite green in some samples of eight species of freshwater fish. Democratic Party legislator Fred Li Wah-ming, chairman of the Legislative Council's food safety and environmental hygiene panel - which will question Dr Chow tomorrow - was dumbfounded some accredited farms did not exist. 'It is very shocking. This is really a scandal. The head of Guangdong province has to tell us what is happening,' he said. The State General Administration of Quality Supervision, Inspection and Quarantine said it was not aware some of the designated fish farms were vacant or had ceased operation. It pledged to investigate. Zhuhai inspection and quarantine bureau chief Chen Bo-wen said: 'I can guarantee you our officials have carried out thorough inspections at [all the eight] registered [city] fish farms [on the list].' Hong Kong fishmongers will resume freshwater fish sales today after a three-day stoppage. About 100 catties of fish arrived last night from Shunde, Guangdong, and sources estimated a further 20 tonnes would arrive today.