Fonterra has admitted sending Palmerston North Girls' High School a potentially contaminated whey protein concentrate after it was requested for use in a science project.
The dairy company this afternoon revealed it sent 12kg of the concentrate, which may have been contaminated with a bacteria that can develop into botulism, to the school after a request in December last year.
Health Minister Tony Ryall said some students may have consumed drinks with the product in them.
However, it was unlikely any were infected with the botulism-causing bacteria, he said.
"While some students may have consumed drinks with the product in them, it was last consumed on 19 April 2013."