Pregnancy Choice co-ordinator Janice Tetley-Jones said the scare was a dreadful thought for mums who used baby formula.
"It's horrific to think a baby would become the victim of something like this, at the pregnancy support we are here to support mums, to help them with their babies to help the general health of babies," Mrs Tetley-Jones said.
"So something like this is very scary for mothers, we certainly would be doing everything we can to inform mothers and make sure the right choices were made surrounding feeding."
About 50 mothers who used her services would bottle-feed their babies with formula.
"It's definitely a major concern for the wellbeing for the baby and the mother."
Tauranga mother Gemma Blacklock said she did not use formula to feed her 11-month-old baby but was concerned about the scare.
"If we were using formula I'd probably think about changing fast because I wouldn't want any chance of that going into my baby," she said.
...when you can't breastfeed and your baby is under 1 years old you don't have much choice but to buy formula
Bay of Plenty Times readers on Facebook also voiced their concern over the threat.
"Of course it concerns us as parents and unfortunately when you can't breastfeed and your baby is under 1 years old you don't have much choice but to buy formula [sic]," Amee Hudson posted.
On Facebook, Jo Henderson said she would be cautious when buying formula from now on.
"It concerns me, however what concerns me more is that it took so long for us to be told. I will continue to use formula, however I will be triple checking the tin I buy!!!"
What to do
* Parents with any concerns could call Plunketline on 0800 933 922 or Healthline on 0800
611 116 for advice.
* The Ministry of Health said anyone who suspected tampering could contact 0800 723665 to report suspected tampering.
* Anybody who suspected their formula had been tampered with could also take it to their nearest police station.
* If cans or bottles of formula had tears, rips, holes, punctures or noticeable bulges, it was possible the product inside had been tampered with.
* Visit www.foodprotection.govt.nz for more advice on how to check packaging for signs of tampering, and for information about government's response.
* Police said those who had information about the threats should call the Operation Concord team on 0800 723 665, or the independent group Crimestoppers on 08000
555 111.
