NZX said it was not aware of a link between yesterday's announcement by the Ministry for Primary Industries (MPI) about the threatened contamination of New Zealand baby formula and sharp falls in milk powder futures prices last week.
Before Tuesday's announcement, sharply lower futures prices had been put down to extra supply coming on stream from Fonterra.
The June whole milk contract went from US$3350 a tonne on March 3 to US$2850 a tonne on March 6, a fall of US$500 or 15 per cent.
Over the same days, the September contract went from US$3450 a tonne to US$3000, down US$450 or a fall of 13 per cent.
"Dairy markets appear to have caught early wind of the threat with milk futures prices falling significantly over the last week," ASB Bank said in a commentary.