Chemist Warehouse Takanini confirmed an internal investigation was also under way.
The mother alleged the formula tin was fully sealed when it was opened.
The mum of two, who did not want to be named, said she noticed what looked like tiny insects moving inside the powder after opening the tin on Saturday .
“You need really good eyes to spot it, like, it was, like, a really tiny one at first,” she said.
“But then when my husband dug into it, he found more.”
The tin was sealed at the time of purchase and showed no visible holes in its packaging, she claimed.
“We just went and returned it to Chemist Warehouse, and then we dug it in front of the cashiers as well.
“And then we found more inside.”
The baby formula was sold at a Chemist Warehouse store in Takanini last week. Photo / Warren Buckland
The family received a refund upon returning it to the store.
“It was a bit disturbing because, you know, we’re dealing with babies here,” she said.
“We’re presuming the whole batch might be infested, so we just switched to the other formula.”
In a statement, Danone said it takes customers’ concerns “extremely seriously” and that all batches undergo extensive testing, including for foreign matter, before being released to market.
“As soon as we were notified of this complaint, it was escalated to our quality team for further analysis.”
Danone also said scorched milk particles can occasionally appear in infant formula products.
New Zealand Food Safety has confirmed it is investigating the complaint.
“[They’re] a common occurrence in the milk manufacturing process and, although unsightly, they are harmless and do not pose a risk to food safety,” the company said.
“From our conversations with consumers, we know that storage conditions in the home are a critical factor for maintaining the integrity of the product once it’s opened.
“Infant formula products should be stored in a cool dry place. After opening, the container should be kept airtight; avoid leaving the tin open on counters, and consume the contents within four weeks.
“If the foil security seal is damaged or missing when opened, do not use the product.”
At this stage, Bishop said scorched particles could be a possible explanation but confirmed NZ Food Safety would independently test the product.
“We have contacted the manufacturer and will visit them and the retailers to establish the facts.”
She emphasised that if a wider issue was identified, “we would take immediate action to address the risk and keep consumers safe”.
Infant formula manufacturers were required to follow strict rules to ensure their product’s safety, with regulated environments and systematic checks at the production point, Bishop said.
Sign up to The Daily H, a free newsletter curated by our editors and delivered straight to your inbox every weekday.