A Marton mum still does not know what the red flakes she found in her baby's food were.
Police have confirmed the red flakes in the baby formula were not pest poison 1080 but no further testing will be done to find out what they are.
Kayla Paranihi says she found the flakes in the Nurture Infant Formula 1 she bought from Marton New World on March 17. She had used the formula several times and noticed her 8-month-old son had been unwell.
Miss Paranihi was interviewed by police and the formula was taken away to be tested for 1080, following news of a threat to poison baby milk powder around the country in an effort to force the Government to stop using 1080 for pest control.
Police told her last week that the formula tested negative for 1080 but they did not know what the substance was, she said.
"I thought when it got analysed, they analysed it to see what it actually was as well," Miss Paranihi said.
She was concerned that she still did not know what the substance was and whether her son Michael had ingested anything harmful.
He had not been eating or sleeping properly in the days after she purchased the formula.
Police would not comment on individual cases but said any samples taken for testing by police had come back as negative for 1080.
"This appears to confirm the police view that the issues being raised by the public relate to matters arising from manufacturing and handling," a police spokesman said.
"However, any suspect tins of product reported to police will be thoroughly assessed and sent for further testing if required."
Police media relations manager Grant Ogilvie said that from a police perspective no further testing was deemed necessary "in order to advance the Operation Concord investigation".
New World spokeswoman Antoinette Laird said the product has been returned to shelf "following advice from MPI and the supplier".
Supermarkets around Wanganui still had measures in place to inform shoppers about the threat. New World and Pak'n Save both had informative signage, and Pak'n Save had moved the baby formula to another area and put a limit on how many containers people could buy. Countdown had the baby food section blocked off, with a sign telling shoppers to ask at the counter for it.
A spokesman for Heinz-Wattie, the makers of Nurture, could not be reached for comment by deadline.