INFANT formula manufacturer Danone has confirmed it is investigating UK reports that a new formulation of Aptamil there is making some babies unwell.
According to the BBC hundreds of British consumers have complained on social media about the changes.
Danone UK said it had undertaken extensive quality and safety checks and was confident the Aptamil range was completely safe.
The company said it had also updated the mixing instructions on the packs because the new formula requires users to shake the mixture vigorously for ten seconds to dissolve the powder.
Other complaints have centred on a reduced package size, despite the price remaining unchanged.
Danone Australia/New Zealand has confirmed the affected formulations are not sold here.