Hong Kong said Sunday it found two Cadbury chocolate products contained considerably more of the industrial chemical melamine than the city's legal limit in a growing scandal over tainted food made in China.

Iran banned imports of all dairy products from China because of the contamination concerns, state radio reported.

In China, the food safety watchdog said no traces of the melamine were found in new tests of milk powder sold domestically, as officials sought to restore public trust in dairy products.

Baby formula containing melamine has been blamed for killing four infants and sickening more than 54,000 with kidney stones and other ailments in China.

Chinese authorities suspect suppliers trying to boost output diluted their milk, adding melamine because its nitrogen content can fool tests measuring protein content.

The scandal has sparked global concern about Chinese food imports and recalls in several countries of Chinese-made products including milk powders, cookies and candies.

Hong Kong's food safety agency said samples of two chocolate products made by British candy maker Cadbury at its Beijing factory contained considerably more melamine than the city's legal limit of 2.5 parts per million.

The two items were among 11 Chinese-made products that have already been recalled by Cadbury in parts of Asia and the Pacific.

Hong Kong's Center for Food Safety said Cadbury's Dairy Milk Hazelnut Chocolate Bulk Pack contained 56 parts per million of melamine, while Dairy Milk Cookies Chocolate contained 6.9 parts per million.

Calls to Cadbury offices in London and Asia Pacific went unanswered Sunday.

In Iran, the Health Ministry said the ban on imports of dairy products from China is in place until further notice, according to state radio. The ministry is assigning health workers to destroy suspect Chinese dairy products currently on the Iranian market.

China's government has been struggling to contain the damage from widespread contamination of milk supplies, castigating local officials for negligence while promising to keep stores supplied with clean milk.

The latest tests of 129 batches of baby formula and 212 batches of other kinds of milk powder showed they were free from melamine contamination, the General Administration of Quality Supervision, Inspection and Quarantine said on its Web site.

The tests were on baby formula and other kinds of milk powder produced after Sept. 14, when the scandal broke, the watchdog said. Quality supervisors have been stationed in baby milk powder production facilities to oversee the process.

The Agriculture Ministry said it is providing subsidies to Chinese dairy farmers badly hit by declining demand for milk. Many farmers have been tossing out raw milk as they are squeezed by feed costs they cannot recoup due to waning demand.

The ministry's statement did not give details of the subsidy plan.