The toxic substance melamine has been detected in chocolates imported from China but there have been no reports of damage to health, the Osaka city government said.

The municipal government said a preliminary test showed that 54 parts per million of melamine has been contained in a product named Chocolate Pillows imported by the Osaka-based company NS International Co.

The case came to light when a Kumamoto Prefecture inspection detected the toxic substance in the product sold at a Kumamoto supermarket. The Kumamoto government passed the information to Osaka City.

The Osaka government ordered the company to recall 85,908 packages that bear the same expiration date – April 14, 2009 – as the one from which melamine was detected, on the grounds that the company may have violated the food sanitation law.

NS International has imported about 798,000 packages of Chocolate Pillows since January and sold them to at least 19 companies in 17 prefectures.

The Osaka city government plans to inspect three other sweets that were made at the same factory and imported by NS International. It has ordered the company to voluntarily stop shipping and selling two of the three sweets as they contain milk-based ingredients.

"We will recall all Chocolate Pillows that are in the market," an official of NS International said. "We contacted all companies that bought the products directly from us. We believe the products are being sold at retailers and supermarkets, but we don't have detailed information yet."

Melamine, a chemical synthesized from urea and ammonia, can trigger the formation of kidney stones if ingested.