Wet nurse prostitutes catering to adults with a breastfeeding fetish were arrested in China, according to South China Morning Post.

Fifteen people were arrested in connection to websites that hired mothers of newborns to breastfeed adults. Over 200 people across the country paid for breast feeding and sex through these websites. The Ministry of Public Security worked with police from Beijing and Hebei to stop the two gangs involved in the prostitution ring, according to SCMP.

A mother involved in the ring told an undercover reporter that offering breastfeeding isn't enough to get regular customers - sex had to be on the menu as well, according to SCMP. Breast feeding was offered to the journalist for 1,000 yuan ($163 U.S.) and sex was priced at 1,500 yuan ($245 U.S.). The services were offered as a monthly package on some websites, the prostitute said, according to SCMP.

Wet nurses servicing adults can take home $2,600 (15,913 yuan), according to International Business Times, which is four times the average monthly income in China.

In order to supply customers, the new mothers breastfed their babies once a day or stopped breastfeeding their child altogether.

"Adult (clients) can drink it directly through breastfeeding, or they can always drink it from a breast pump if they feel embarrassed," Lin Jun, owner of Xinxinyu, a company that provided the service, told IBT.

Milk fetishism is also called "lactophilia."