The programme said that by adding permeate to milk, production costs can be cut.

Permeate is a by-product of cheese production.

Internal documents from Australia's biggest supplier, National Foods - which makes Pura, Big M, Dairy Farmers and supplies both Woolworths and Coles brand milk - reveal its milk now contains up to 16.43 per cent permeate. One document, labelled ''permeate cost savings'', reveals up to $22,960 can be saved by adding 16 per cent permeate to the production of 350,000 litres of whole milk. This shaves almost 16 per cent of the cost off the price of production, and does not have to be disclosed on the label.

Food Standards Australia New Zealand controls the composition of milk, and allows producers to add milk components such as milk permeate so long as the total fat and protein levels remain at a minimum level.

WAFarmers Dairy Section President, Peter Evans, said at a time when the Western Australian dairy industry was struggling for survival, WAFarmers is appalled that Today Tonight would seek to undermine Australian milk products through the provision of misleading information to consumers.

“The Australian dairy industry produces a range of consistent, safe and highly nutritious products,” Mr Evans said.

“Permeate is produced when milk is passed through a sieve (ultrafiltration) to separate the milk-sugar (lactose), vitamins and minerals components from milk protein. Permeate is a natural product of milk processing and not a foreign additive as suggested by the programme.

“Dairy manufacturers may adjust these components to produce a variety of different types of milk such as low fat, high calcium, no fat, to meet customer demands.

“The composition of milk is governed by the Food Standards Australia New Zealand (FSANZ) Food Standards Code, which ensures consumers purchase nutritionally consistent, high quality and safe products.”

Mr Evans said the FSANZ Food Standards Code allows processors to adjust the components of milk delivered from farms, when necessary, to produce a wide variety of nutritionally consistent and safe products.

WAFarmers urges consumers to disregard the alarmist propaganda and continue to enjoy the wide range of highly nutritious Western Australian dairy products available for consumption.