New mothers in public hospitals in New South Wales have been given the wrong baby to breastfeed.
The ABC reports there have been more than 20 such cases over the past three years.
NSW State Premier Kristina Keneally says the mix ups were "totally unacceptable".
She says new rules were introduced in March, making it mandatory for babies to be kept with their mothers in their rooms, unless there was a good clinical reason preventing it.
The NSW Health Department has moved to reassure the public after the disclosures emerged.
It says there have been no known instances of it happening since the new rules were put in place.