A woman said to have been in a vegetative state for at least a decade at a private healthcare facility in Phoenix reportedly gave birth, triggering a police investigation and reviews by state agencies in a situation that the state governor’s office called “deeply troubling”.

Azfamily.com, a news website for television stations KPHO and KTVK, first reported late on Thursday that according to sources not identified, a woman gave birth on 29 December, while living at a Hacienda HealthCare facility, where the staff was unaware that she was pregnant.

Two other Phoenix television stations aired similar reports. According to some reports, the woman was a victim of a near-drowning more than 10 years ago. Her identity was not reported, and was not immediately known if she has family or a guardian.

Healthcare staff were initially unsure why the woman was moaning, the reports said. Sources quoted said the baby’s head was starting to emerge when a nurse came in.

“None of the staff were aware that she was pregnant until she was pretty much giving birth,” azfamily.com quoted a source familiar with the situation as saying. That person said the baby was said to be alive and healthy.

Following the azfamily.com report, Hacienda HealthCare and state officials issued brief statements, expressing concern and describing reviews being conducted and steps being taken. They did not specifically confirm the reported pregnancy and birth.

A Phoenix police spokesman, Sgt Tommy Thompson, said the “the matter is under investigation”. He declined to confirm whether the investigation involved a possible sex crime or elaborate on the circumstances that prompted the investigation.

Hacienda said it was cooperating with law enforcement and reviewing its security protocols after becoming aware of a “deeply disturbing incident and “an unprecedented matter”.

“While federal and state privacy laws prohibit us from publicly discussing a patient’s health or case, Hacienda has and will continue to cooperate fully with law enforcement and all the relevant regulatory agencies regarding this matter,” the company said in its statement.

Hacienda spokesman David Leibowitz told Reuters the facility had recently become aware of a “deeply disturbing incident” involving a resident. He declined to say whether staff were being asked to undergo DNA testing, or whether the facility was taking any preventative measures to protect patients against a similar situation.

Victim advocate Tasha Menaker, chief strategy officer of the Arizona Coalition to End Sexual and Domestic Violence, said it would be appropriate for police to run DNA tests on male employees at the facility.

Hacienda’s website said it serves infants, children and young adults who are “medically fragile” or have developmental disabilities.

Governor Doug Ducey’s office said the Republican was briefed on the “deeply troubling” reports as soon as the office learned of them and that state agencies “immediately began taking every measure to protect patient safety”.

According to the Arizona Department of Health Services, an agency that regulates healthcare facilities, the 60-bed Hacienda facility was required to tighten security procedures to protect patients in wake of the report.

“We are aware of this situation and are actively working with local law enforcement in their criminal investigation,” the department said in a statement.

The state Department of Economic Security, a social-service agency whose functions include serving disabled people, said it performed health and safety checks on all of the residents at the Hacienda facility after the birth was reported and was working with police on their investigation.