New Zealand Ministry of Primary Industries (MPI) on Saturday released details of one Fonterra- sourced product on the New Zealand market that may potentially contain a botulism-causing bacteria.

The dairy company has said the bacteria Clostridium Botulinum was found in three batches of its whey protein - a product used in many foods including baby formula and sports drinks.

The ministry said five batches of Nutricia Karicare follow-on formula products for children from 6 months old potentially contained contaminated whey protein.

Nutricia said three of those batches are in a warehouse in Auckland, one is on a ship, and the other is in storage in Australia. The company has locked down those batches, and they will not be sold on the market.

Earlier, Fonterra refused to say which companies may have used the whey product containing the bacteria. Fonterra New Zealand Milk Products Managing Director Gary Romano said the company could not say more because of commercial sensitivities.

The Ministry for Primary Industries said it has contacted appropriate regulatory authorities overseas, and is focusing on ensuring there are no contaminated products on the New Zealand market.

The 38 tonnes of whey protein affected was produced in May 2012 and the company said a dirty pipe at its Hautapu plant in Waikato was responsible for the contamination.

The dairy firm said Saturday most of the protein was sold to eight manufacturers to make their own products.

Fonterra said none of its brands are affected, but will not rule out whether other brands on the shelf in New Zealand are. There had been no reports of illness linked to the consumption of the affected product and fresh dairy products - including milk, cheese and yoghurt - had not been affected, the company said.

Fonterra said a product tested positive in March for Clostridium, which could have been one of a number of strains, most of which are harmless. Over the following months product samples were put through intensive testing, and on Wednesday tests indicated Clostridium Botulinum in a sample.

The particular whey protein concentrate concerned, WPC80, is used by Fonterra's customers in a range of products including infant formula, growing up milk powder and sports drinks.

Botulism is one of the most dangerous forms of food poisoning and can lead to paralysis that cause people to stop breathing.