Two samples of canned dace, or mud carp, on sale in supermarkets and a live tiger grouper from a Cheung Chau wet market tested positive for the cancer-causing chemical malachite green during routine tests.
The Food and Environmental Hygiene Department released the findings yesterday after it tested 26 samples.
'Among them, three samples, comprising one live tiger grouper and two canned mud carp, were found to have the chemical,' a department spokesman said.
Last week the government was criticised for being too slow in warning the public about other samples of tinned dace that had tested positive. The government defended itself by saying that the amount of malachite green found was so low it was considered borderline whether or not to reveal the brand names affected.
Department officials said they had contacted retailers and wholesalers to stop the sales. They stressed that malachite green was banned in all food sold in Hong Kong.
Last night ParknShop and Wellcome voluntarily withdrew the cans from their shelves.