South African police have arrested a woman who sold  her 19 month old baby on the Internet for 5,000 rand ($380) and will charge her with human trafficking in court on Friday, a special crime unit said.

The 20-year-old woman was arrested during an undercover operation following a tip-off from a member of the public that a baby was being sold on the website Gumtree,  a classified advert site, the Hawks police unit said.

“What we have already ascertained is that the baby is not hers and the baby is now with the care of social workers,” Hawks’ spokesman Hangwani Mulaudzi told Eyewitness News. The money was also recovered from the woman.

“We are trying to ascertain where this baby comes from and what exactly were this woman’s intentions.”

The woman’s identity has not been made public, so it was not possible to contact her for comment.