Police in Arizona are reportedly seeking DNA samples from male staff at a nursing home where a patient in a vegetative state gave birth.
The incident occurred at a clinic run by Hacienda HealthCare, near Phoenix.
The centre said a warrant was served by police on Tuesday, as authorities try to find out how the vulnerable woman became pregnant.
Earlier this week, the chief executive of the corporation in charge of the home resigned over the case.
On its website, Hacienda HealthCare says it provides care for “medically fragile and chronically ill infants, children, teens, and young adults as well as those with intellectual and developmental disabilities”.
The female patient, who has not been identified, had reportedly been at the clinic for more than a decade before she gave birth to a baby boy on 29 December.
‘Outraged, traumatised and in shock’
Lawyer John Micheaels, representing the woman’s family, described her as being in a “completely vulnerable state”.
“The family obviously is outraged, traumatised and in shock by the abuse and neglect of their daughter at Hacienda HealthCare,” Mr Micheaels told NBC’s 12News.
Her family, who say they are not ready to come forward, also asked for it to be conveyed publicly that the child has been “born into a loving family and will be well cared for”.
Local media reports say staff at the care home were unaware the patient was pregnant until she gave birth.
Hacienda has said it will “do everything in [its] power to bring this police investigation to a quick conclusion”.
“We will continue to cooperate with Phoenix police and all other investigative agencies to uncover the facts in this deeply disturbing, but unprecedented situation,” it said in a statement.
The company also said it had sought legal advice over the possibility of mandatory DNA testing for staff, but was advised it would violate federal law.
Arizona Department of Health Services said additional safety measures have been implemented at the home since the case came to light.