http://abcnews.go.com/US/wireStory?id=3055637&page=1
"The source of the melamine remains unclear. It may have contaminated the rice protein through the reuse of dirty bags used to ship the products."
"The Las Vegas importer of the contaminated Chinese wheat gluten, ChemNutra Inc., that led to the original pet food recall has suggested that spiking a product with melamine can make it to appear to be richer in protein during tests, thus increasing its value."
"The source of the melamine remains unclear. It may have contaminated the rice protein through the reuse of dirty bags used to ship the products."
"The Las Vegas importer of the contaminated Chinese wheat gluten, ChemNutra Inc., that led to the original pet food recall has suggested that spiking a product with melamine can make it to appear to be richer in protein during tests, thus increasing its value."