China's current milk crisis has revived a tradition once frowned upon by the Communist government as bourgeois: the wet nurse.

Chinese mothers are posting online ads for to sell breast milk, and agencies that recruit household help are fielding a record number of requests for families seeking wet nurses.

In some case, poor mothers are finding they can sell their own milk for up to 10,000 yuan a month, the equivalent of a year's salary for a manual labourer.

A Sichuan woman named Huang told CBC News her phone has been ringing off the hook ever since she put an ad on the internet offering to sell her breast milk.

"I've got my baby," she said through a translator. "And it seemed like a shame to waste the extra milk."

Huang sells her milk to one couple with a four-month old baby for about $500 a month.

In Shenzhen, southern China, a wet nurse agency that employs 35 women reports it is busier than ever because of the melamine contamination that has sickened more than 53,000 babies.

According to Ai Xiaoxiong, human resources manager for Shenzhen Zhongjia housekeeping company, the price for breastfeeding sessions has more than doubled to $1,750 US a month.

At the Rain Household Care Co. in Guangzhou, the number of wet nurses has doubled to six since the scandal began, founder Zheng Rong said.

China has seen a decline in the number of mothers who breastfeed, largely because more women are in the workforce. Many of them are migrants who leave their infants with grandparents to work in the city.

The use of baby formula has also become a status symbol among the growing middle class. Many have been persuaded to use formula because of claims by dairies that powdered milk will make their baby smarter.

The World Health Organization has redoubled its efforts to promote breastfeeding in China, saying all infants should be fed exclusively with breast milk for the first six months of life.

With files from the Associated Press