Hong Kong's Centre for Food Safety confirmed a Singapore laboratory's finding of melamine in White Rabbit Creamy Candy, and stores in Shanghai began clearing the sweets from shelves even though its maker has still not initiated a recall.
The centre warned the public not to eat the popular mainland sweet or Four Seas strawberry-flavoured cake, which also contains melamine, tests show, and asked shops and their suppliers to stop selling them.
Consuming normal amounts of either product would not make a three-year-old ill, it said.
The tests found 4.6mg per kilogram of melamine in the candy and 6.1mg per kilogram in the cake. Both exceed the melamine limit of 2.5mg per kilogram permitted under a regulation which took effect yesterday.
However, the centre said the products' distributors would not face prosecution under the regulation since it took samples of them for testing before it became law.
Some Shanghai stores have voluntarily withdrawn White Rabbit candy from sale. The supermarket group which owns the Kedi convenience store chain ordered staff to withdraw the sweets from sale.
The Shanghai-based Bright Food Group, which owns White Rabbit candy producer Guan Sheng Yuan Group, said a testing agency was checking the candies, and it would decide whether to recall its products after receiving the results.