Ministry for Primary Industries (MPI) said the buckwheat flour was supplied by Davis Food Ingredients.
The agency said it was continuing to trace affected flour to businesses around the country.
The firm told us that it only imports small amounts of buckwheat flour and makes no claim that the product is gluten free to customers but believes some downstream customers may have been making such claims.
One person has reported a reaction after consuming products made using the affected buckwheat flour and there have been self-reported reactions on social media.
Pizza bases, bread, chocolate chip cookies, pancake mix and ready meal products are affected.
MPI said as testing was by food businesses and provided to it, due to reasons of confidentiality it could not tell us about the levels of gluten found in products.
"The testing for gluten was initially done by a food business that had received the buckwheat flour for use in one of their gluten free products. This testing was done as part of routine checks on incoming ingredients to ensure the product matched the specification provided by the supplier and to ensure that the claims being made by the company could be substantiated," the agency told FoodQualityNews.
"As a result of gluten being detected, a recall of that product was carried out. MPI then contacted the importer and supplier (Davis Food Ingredients) and additional testing was done."
MPI said initial efforts were focused on mitigating risk.
"This involved working with the company to trace product and ensure all food businesses who had received the product were contacted and product recalls carried out where required. Now we are working to find out what caused this and what actions need to be taken to prevent a recurrence. As part of any investigation we also assess whether enforcement action is required.
"MPI is reminding all food businesses to ensure they have robust supplier approval processes in place and that suppliers provide evidence of any claims they are making about the presence or absence of allergens. This includes testing by accredited laboratories. In the absence of such evidence food businesses can arrange their own testing."
Gluten intolerance or coeliac disease
Melinda Sando, MPI’s manager food compliance services group, said the gluten containing buckwheat flour was used in products advertised as gluten-free and items that consumers consider to be gluten-free.
"To protect people who are gluten intolerant or have coeliac disease, these products have been and are being removed from shelves,” she said.
"Most of our trace back work is complete but we may expand the number of products recalled if we receive evidence that affected buckwheat flour is being used in products advertised as gluten free or in products consumers consider to be gluten-free.
"We have asked the company to confirm the cause of this issue and to ensure that in addition to mitigating the risk to consumers, that appropriate actions have been put in place to prevent a recurrence of this nature."
Venerdi recalled all batches of its Venerdi brand Gluten Freedom Fancier Sourdough Pizza Bases due to the problem.
Gluten Free Holdings recalled specific batches of its Gluten Free Choice brand Multigrain and Seed bread and Chia Seed bread due to the undeclared allergen.
“We have been informed by MPI that the buckwheat flour we used from 3 October to 18 November showed signs of gluten contamination. If you have purchased BW Seed or BW Plain Loaves or the rolls they might have been affected," said the Totally Gluten Free Bakery.
“Please check your freezer and dispose of any product. We sincerely hope that [no-one] was ill affected by this occurrence and apologise for any unnecessary inconvenience.”
CuisAnn is taking action for certain batches of its CuisAnn brand Curried Vegetable Pie, Bacon Quiche, Chicken Quiche, Gluten Free Savoury Pastry, Lentil Lasagne, Curry Chicken and Kumara Pie, and Beef Lasagne due to gluten.
Bin Inn Retail Group recalled specific batches of Buckwheat Flour, Gluten Free Store recalled a batch of its Buckwheat Pancake Mix and Bay Drive recalled a batch of its brand chocolate chip cookies.