Down Under parents are desperate to feed their babies the natural elixir, creating a black market boom in breast milk.
They are being charged up to 1000 dollars a litre on the Internet.
Breast milk provides antibodies that protect babies against diseases and is especially important for premature babies.
One of the mothers contacted the Gold Coast based Mother's Milk Bank to ask what the real "going rate" was for breast milk after online sellers sought an exorbitant amount when she placed a web advert seeking human milk.
Mother's Milk Bank director Marea Ryan told her that the not-for-profit bank sold milk for 50 dollars for 1.2 litres.
"I think it is increasing more and more as people become a lot more aware of the benefits of breastfeeding," the Courier Mail quoted Ryan as saying.
RMIT (Royal Melbourne Institute of Technology) lactation expert Dr Jennifer James said she was aware of the growing unregulated black market.
"It is very dangerous because in an unregulated fashion there are no checks and balances, the milk would not have been tested for viruses and bacteria," said James.
"Women are being put in this insidious position because of a lack of breast milk banks nationally.
"They have no option but to look outside the system," she added.
Black marketing of breast milk has increased with the advent of the Internet where women advertise.
James said there should be breast milk banks in all major hospitals but blamed inconsistent legislation for making them difficult to set up.