An Arcadia couple arrested two months ago on suspicion of child neglect after their 2-month-old baby boy was hospitalized and whose 21 other children were taken away, remain under investigation, police said.

It wasn’t clear how many of the children, ranging in age from two months to 13 years old, were born from surrogate mothers. Several women told KTLA they bore children for Silvia Zhang and contracted with Mark Surrogacy Investment.

Public records show Zhang is listed as manager for Mark Surrogacy and her residence on the 600 block of West Camino Real Avenue is the same address for the company. An agent for the company filed a document with the state ending the company on June 13. Zhang is also listed as a manager for another defunct company called Hope Surrogacy in Pomona.

Zhang, 38, and her husband, Guojun Xuan, 65, couldn’t be reached for comment on Wednesday.

The couple said they wanted a large family, Arcadia police Lt. Kollin Cieadlo said.

The primary focus by police is the child-abuse case, but they are working with the Los Angeles County Department of Children and Family Services and federal officials to determine if there were other crimes, he added.

Zhang and Xuan haven’t been arrested on charges related to the other children or Mark Surrogacy.

FBI spokeswoman Laura Eimiller said she cannot confirm or deny an investigation.

The 2-month-old baby remains in the hospital, Cieadlo said.

It wasn’t clear if the baby’s siblings are in foster care or with relatives. The Department of Children and Family Services declined to say.

“While we recognize the public’s interest in the details about the lives of children and families who come to our attention, DCFS is bound by state confidentiality laws that prevent the department from discussing potential involvement with families,” said Shiara Davila-Morales, a DCFS spokeswoman. “These laws are in place to protect children and families from further emotional distress while delicate family matters are resolved.”

Police say that surveillance video shows the nanny, Chunmei Li, 56, of Arcadia, on May 5 violently shaking and hitting the baby who became unconscious. There is an arrest warrant out for Li who has not been found.

The baby wasn’t taken to a hospital until two days later, after he started having seizures, police said, adding  that the infant was admitted with traumatic head injury and intracranial bleeding.

The hospital staff notified police about possible child abuse.

On May, 9 police arrested Zhang and Xuan on suspicion of felony child endangerment or neglect. Booking records show they were released from custody on May 13. They have not been charged.

DCFS took other children into protective custody that day. Fifteen of them were in the Arcadia house, which, according to public records, has nine bedrooms and 12 bathrooms in 10,287 square feet. The other children were in other Los Angeles County residences, Cieadlo said.

Arcadia police asked anyone with information about the case to call them at 626-574-5168. Anonymous tipsters can call Crime Stoppers at 1-800-222-8477 or go to lacrimestoppers.org.