"We have been through a thorough investigation which included consultation with our engineers who confirmed the ball bearings we have in our plants are not the same size as the one the customer found in their icecream.
"We are confident in our testing procedures and that the ball bearings were not in the icecream when it left the factory.''
The group is now investigating when - after leaving its factory - and how the ball bearings have come to be that particular icecream tub.
Howick woman Ann Brown said her family had been enjoying a Sunday night dinner, on September 16, when her daughter found the first ball bearing while eating some icecream her mum had just scooped for her.
"My daughter started eating the ice cream. She called out an expletive and spat out a large ball bearing onto her hand,'' Brown told Radio NZ.
It was first thought that it was an edible silver ball used in cake decorating.
"But it was much bigger and when she went through her ice cream, there was another 10 in there.''
The product in question was Kāpiti Ice Cream's triple chocolate flavour ice cream, RNZ reported. The company is owned by the Fonterra group.
Fonterra acknowledged they had been in touch with Brown and that she had been dissatisfied with their explanation.
"We will be contacting her in person to discuss further.''