Police in California have rescued 21 children who were born through surrogacy. The children were found in the home of a couple who are now accused of running a strange and troubling surrogacy scheme.

The investigation began after police were called about a two-month-old baby with serious head injuries. When officers arrived at the couple’s home in Arcadia, they found 15 children aged between two months and 13 years living there.

Authorities later discovered that six more children connected to the couple were already living in other homes. This brought the total number of rescued children to 21.

All the children have been linked to 65-year-old Guojun Xuan and 38-year-old Silvia Zhang. The couple was arrested for felony child endangerment but have since been released.

Police are now looking for the couple’s 56-year-old nanny, Chunmei Li. She was caught on a camera shaking the baby violently back in May. Sadly, the baby was hurt, and the couple waited two days before taking the child to the hospital. The baby is still being treated.

Most of the rescued children—17 out of 21—are under the age of three. Investigators say all the children were born through a surrogacy business secretly run by Zhang and Xuan.

“It’s horrific, it’s disturbing, it’s damaging emotionally,” said Kayla Elliot, one of the surrogate mothers. Elliot said Zhang and Xuan claimed they only had one other child. But two months after she delivered their baby, she learned the child had been removed from their custody. She is now seeking to gain custody.

“These agencies — we’re supposed to trust them, follow their guidance, and come to find out this whole thing was a scam,” Elliot said. “The parents owned the agency. That was not disclosed at all.”

One surrogate, a woman named Elliot, later found out she wasn’t the only one. Surrogates from places like Texas and Florida realized they had also been tricked into helping the same couple. In one sad case, a Florida surrogate gave birth to a stillborn baby in June. Two other women in Los Angeles said they had delivered babies for the couple in previous years.

All the surrogates said they worked through a company called Mark Surrogacy. But public records showed that this company was registered at the couple’s house. They have now tried to shut down the business, but a woman in Pennsylvania is still pregnant for them—26 weeks along.

“It really hit hard when all of this came through,” the Pennsylvania surrogate told KTLA.

Zhang is listed as the legal mother on all the children’s birth certificates. Police also say they found proof of other abuse involving different nannies. They plan to present this information to prosecutors soon.

Zhang sent a text message to a local news station saying she did nothing wrong and plans to fight any charges in court.

Meanwhile, surrogate Elliot has started a GoFundMe page to raise money so she can try to get custody of the baby she gave birth to.