New Zealand dairy giant Fonterra may be forced to put health-warning labels on its milk, yoghurt, ice cream and milk powder if a lawsuit filed by A2 Corporation is successful. A2 Corporation, which was formed in early 2000 to pursue commercial opportunities arising from studies suggesting beta-casein A1 protein could cause diseases such as diabetes and heart disease, is accusing Fonterra of "misleading and deceptive" conduct regarding the protein.