Maxim's restaurant chain has been ordered to stop selling one of its popular dim sum dishes after an excessive level of melamine was found in a sample. Tests by the Centre for Food Safety found that a mai-lai cake, or steamed sponge cake, contained 3.2 parts per million of the industrial chemical. The legal limit is 2.5ppm. The sample was collected from a Maxim's Chinese-style restaurant at the Island Resort Mall in Siu Sai Wan. A warning letter was sent to the restaurant chain and it was asked to stop selling the product, the centre said. 'In its follow-up action, the [centre] understood that the product in question was made by the food premises concerned. Raw materials for making the product were taken for tests,' a statement said. A three-year-old child would have to eat eight pieces of the cake, or about 1kg, a day to exceed the daily limit, the centre said. A Maxim's group spokeswoman last night said all its Chinese-style restaurants would stop selling mai-lai cake immediately and until further notice. The group's website shows it has more than 20 restaurants around the city. The spokeswoman said an independent lab it had employed to test all of its food ingredients had confirmed they were melamine-free. She was, therefore, surprised by the government's finding. She said the group would follow up the case with the government and suppliers. Meanwhile, the results of 74 samples of other products from various manufacturers were found to be satisfactory. Secretary for Food and Health York Chow Yat-ngok said yesterday the government would gradually scale back the number of tests on food items for melamine over the next three months, from the present 100 samples a day to 100 a week.