The Centre for Food Safety tested 5,600 food samples in June with an overall satisfactory rate of 99.6%. However, 24 samples were found to have excessive or illegal use of food preservatives, veterinary drug residues or colourings, and metal contamination.

It tested vegetables, fruit, meat, poultry, seafood, milk and milk products, frozen confections, cereals and grains.

Five ice-cream bars and five ice-cream samples were found to contain excessive coliform organisms. They were from the first consignments of two brand-new products imported into Hong Kong. All affected batches have been marked and sealed. No stock has been allowed on the market.

A fresh mushroom sample contained the heavy metal cadmium exceeding the legal limit, while a fresh beef sample contained the non-permitted preservative sulphur dioxide.

A frozen prawn sample was found to contain excessive cadmium and a dried fish maw sample contained the preservative sulphur dioxide exceeding the legal limit.

For tests on veterinary drug residues, a grouper sample was found to contain nitrofuran metabolite. A tartar sauce sample was found to contain excessive benzoic acid and sorbic acid while a sesame flavoured crispy stick sample contained the non-permitted sweetener stevioside.

The seven other failed items were announced earlier.

The centre said the exceedances or breaches are not serious. It has traced the source of food in question, stopped their sale and issued warning letters. If there is sufficient evidence, prosecution will be taken.