New Zealand's Fonterra, the world's largest dairy exporter, has found an ingredient in some of its dairy products that contains a strain of bacteria that can cause botulism, with patients showing symptoms of nausea, vomiting and muscle weakness. In the worst cases, it can lead to coma and death if left untreated.

Gary Romano, Fonterra'S Head of NZ Milk Products, said, "We are very, very concerned about human health and we are doing everything possible to minimise exposure. I want to talk about people rather than brands."

New Zealand authorities have triggered a global recall of up to 1,000 tons of dairy products across seven countries. Products include infant formula, sports drinks, protein drinks and other beverages.

Countries affected besides New Zealand are China, Australia, Thailand, Malaysia, Vietnam and Saudi Arabia. China imports the majority of its milk powder products from New Zealand. Chinese authorities have asked domestic importers to recall any products which may have been contaminated by the bacteria and to ramp up scrutiny of New Zealand dairy products coming into the country.