Australian mothers desperate to feed their babies breast milk are advertising for donated human milk in an unofficial exchange that bypasses health authorities.

The trend of buying "black market" breast milk is part of an international return to breast-feeding, according to advocates who say the "breast is best" message is getting through.

A milk bank on Australia's Gold Coast has fielded more than 160 requests from New South Wales women wanting to find or donate milk.

But the interest in black market breast milk is not only occurring in Australia. In the U.S., breast milk has sold online for as much as $1.90 per half ounce, according to the report.

The natural baby food is proven to contain antibodies that prevent illnesses and infection, and has been linked with everything from higher intelligence to fewer allergies.

But mothers without their own supply are desperately looking for ways to obtain breast milk, risking passing on diseases including HIV and hepatitis through the use of unscreened milk.

Mothers Milk Bank founder Marea Ryan said mothers were forced underground because banks — including her own in Queensland, Australia — can only provide a local supply.

"I think it is increasing more and more as people become a lot more aware of the benefits of breastfeeding," she said.

She said mothers should see blood tests before feeding their baby donated milk.

Click here to read more on this story from The Daily Telegraph.