Japanese ham and sausage producer Itoham Foods said it will voluntarily recall 13 products after toxic substances were found at above-standard levels in the water used at one of its factories.

The manufacturer found that underground water used in the facility, located near Tokyo, contained high levels of cyanide ions and cyanogen chloride.

The amounts of the substance were 0.02-03 milligrams per litter, two to three times the levels permitted by Japanese safety standards, but within the World Health Organisation’s (WHO) recommended levels.

According to the meat producer, the amounts are not large enough to cause any serious health damage.

Last week, two leading food manufacturers in the country recalled instant cup noodles following the discovery of insecticide contamination in their products.