Worries about food safety have been mounting in Japan.

Earlier this week nine cups of noodles were found to contain poison, and one maker recalled half a million cups of the popular product.

Itoham Foods said that underground water used in the plant near Tokyo was found to contain cyanide ions and cyanogen chloride at levels that exceeded Japanese standards, but that it did not believe the products, if eaten, would pose a health threat.

Itoham said that it detected 0.02 to 0.03 milligram per litre of the two substances in the water, which is above the Japanese standard but below the standard set by the World Health Organisation.

No health problems have been reported, Itoham official Ryota Suzuki said.

Suzuki said the company would recall 9 types of sausage products and four types of pizza products.

Itoham, Japan's second-largest processor of ham and sausages after Nippon Meat Packers, was set to hold a news conference to brief on the issue at 7.00 pm in Tokyo.

Earlier this year, several Japanese were made ill by Chinese-made dumplings that also contained insecticide, incidents that followed several false labelling scandals involving traditional sweets and cookies made in Japan. -- REUTERS