Elevated levels of arsenic have been found in a range of baby foods - and a New Zealand wholefoods supermarket says it is prepared to pull the products if further warnings come through.
Researchers from Sweden found that feeding infants twice a day on shop-bought baby foods such as rice porridge could increase exposure to arsenic by up to 50 times compared to breast feeding alone.
Exposure to other toxic metals such as cadmium, which is known to cause neurological and kidney damage, increased by up to 150 times, while lead increased by up to eight times.
"These elements have to be kept at an absolute minimum in food products intended for infant consumption," said the researchers from the Unit of Metals and Health at Karolinska Institutet in Stockholm, Sweden.
The products tested were made by major baby food manufacturers including Organix, Hipp, Nestle and Holle - some of which are available at New Zealand stores.
Holle organic rice porridge was found to contain 7.3 micrograms of arsenic per portion - the highest found in the study - along with 0.38 micrograms of cadmium and 0.26 micrograms of lead.
It is sold at Auckland wholefoods supermarket Huckleberry Farms and several online New Zealand retailers.
Huckleberry Farms general manager Dave Spalter said the store had stocked the infant porridge because it was a certified organic, European product.
"We like to think the products we stock are superior to many of the other brands. Our customers wouldn't want us to take a knee-jerk reaction, but we wouldn't wait to pull the product from our shelves instantly if there was a problem with it, or if it was worse than others."
He would be making further inquiries about the products, Mr Spalter said.
"It's a bit hard to quantify at the moment, but if information comes through that it's not good, we will react appropriately."
The high concentrations of arsenic in rice-based infant foods were of particular concern, the study said.
"Alarmingly, these complementary foods may also introduce high amounts of toxic elements such as arsenic, cadmium, lead and uranium, mainly from their raw materials," they wrote in the Journal of Food Chemistry.
None of the levels of the toxic elements exceeded official safety limits, and New Zealand Food Safety Authority principal toxicology adviser John Reeve said the heavy metals were not known to cause acute problems.
"They're all very long-term toxins ... What's important is not what happens as an infant, it's what happens over many years," Dr Reeve said.
The authority would investigate the baby foods highlighted in the Swedish report, he said.