A Geelong, Australia, woman could lose custody of her children after she tried to sell them on eBay, official say.

The woman, who is in her 30s, put photos of her son and daughter, both under 10 years old, last week, apparently as a joke, the Geelong Advertiser reported Monday. The listing was online for one day last week, and was taken down after police contacted eBay.

The police believed the woman's excuse that the listing was a joke and did not press criminal charges, however, the Department of Human Services is still investigating her actions.

"We are conducting an investigation to ensure the children's welfare and safety are taken care of and looked after," a human services representative said. "If it is deemed severe and the children were at risk then yes, that would be the case [taking the children off the mother]."

Child advocacy groups are outraged by the stunt.

"I think it's a fairly twisted sense of humor. It's a sick joke and it's distasteful," Kevin Zibell, president of Centre for Excellence in Child and Family Welfare, said.

Victorian Child Safety Commissioner Bernie Geary chimed in, saying, "Children should not be used as the butt of jokes and she needs to find something more productive to do with her time and needs to wake up to herself."