New Zealand's Fonterra - the world's biggest dairy exporter - is under scrutiny over potential GM [genetically modified] contamination in the milk products it sells.
It comes after Greenpeace Australia questioned the controls on dairy farms run by an Australian company in which Fonterra has a controlling stake.
Fonterra refused to answer the environmental group's questions - prompting a red flag in the Greenpeace True Food Guide 2011.
Other food lines to be red flagged include Streets icecream, Continental Soup, Hellmans, Flora and Pro Active, all made by Unilever. Weight Watchers Cereal Bars and Muffin Bars, McCain pizzas and Sara Lee were also flagged.
Fonterra did provide a written statement addressing Herald on Sunday questions. The statement acknowledged that it only limited the presence of unwelcome genetically-modified proteins - it did not always eradicate them entirely.
"We continually strive to minimise unintentional traces of GE content," said Jeremy Hill, Fonterra group director of technology.
He declined to answer questions around where Fonterra's feed is sourced from, and whether the feed is tested for the presence of GM proteins.
True Food Guide co-ordinator Nathaniel Pelle said he had phoned Fonterra's [milk supply] general manager Tim Deane, after not receiving any reply to two written requests for information.
The general manager said the company was not willing to participate in the Greenpeace survey.
Unilever also acknowledged the presence of GM ingredients.
"We cannot claim that all ingredients in our products are GM free," the company said, in a written statement to the newspaper. "Where we cannot be 100 per cent confident on any statement, we will not make it - which is why as a business we don't make 'GM-free' claims in relation to any of our products."
Unilever said its products meet "rigorous safety and quality standards" but the company's complex supply chain made it difficult to avoid GM and GM-derived ingredients.
The products sold by Fonterra, Unilever and the other companies meet the standard, "generally recognised as safe ", as assessed by the transtasman regulatory body, Food Standards Australia New Zealand. The standard allows one per cent of a product to be genetically modified.
In Australia, food containing GM content must be labelled on the packet - but this is not required in New Zealand.
Sara Lee general manager Paul O'Brien issued a statement: "Verification as to the source of ingredients purchased by SLA will be the responsibility of the ingredient supplier."
Weight Watchers said: "The Weight Watchers method ... can be easily followed with or without the use of GM foods. Weight Watchers only uses ingredients which are 'generally recognised as safe'."
McCain, though, rejected its True Food Guide rating, saying the company asked suppliers to certify that the products they supply to McCain Foods did not contain GM ingredients, and conducted spot audits.