Authorities have launched a criminal investigation after video surfaced Wednesday of a police officer pummeling a naked woman as officers attempted to restrain her at Detroit Receiving Hospital.

Video of the incident obtained by WJBK showed officers and security guards grappling with the woman as she cursed and yelled at them. She spat at police before an officer started raining down punches on her head, back and face, WJBK reported.

>> See the video from WJBK (Warning: The video contains violence. Viewer discretion is advised.)

Detroit police Chief James Craig said that the 18-year police veteran at the center of the incident was suspended with pay soon after police got the “very disturbing video” on Wednesday.

“At this point, I can’t tell you why the officer didn’t opt for the Taser, why he didn’t wait for backup,” Craig said Thursday at a news conference. “Those are things that will be determined by this investigation.”

The incident stemmed from a call made around 6:45 p.m. Wednesday of a “lewd and lascivious in progress,” Craig said. Responding officers found the woman naked near Brainard Street and Trumball Avenue. She was not aggressive, Craig said.

Officers determined the woman was likely dealing with a mental crisis, so they gave her something to cover herself with and took her to the hospital, according to the chief.

“I will tell you preliminarily, even though we are very early in this investigation, one of the concerns that I have is the fact that the officer did not handcuff this mentally ill person,” Craig said. “We know from our training and experience that anytime we transport someone -- particularly if they’re suffering from mental illness -- for their safety, for the officer’s safety and for the community’s safety… we handcuff.”

Craig said footage from police body-worn cameras shows that the woman became agitated after police brought her to the hospital.

“She was threatening, clenched fists. She spat on several of the hospital employees,” Craig said. “A member of the (hospital’s) security staff was bitten twice and sustained some injury. At one point she tried to bite the officer who used force.

“So, as he was trying to calm her down, at some point the officer began to strike her because she wasn’t responding, she was not compliant.”

An unidentified woman told WJBK that she started recording video when she saw the situation escalating from a hospital waiting room. Craig said police obtained the video around 8:20 p.m. Wednesday after WJBK alerted them to it.

“What’s troubling for me is we are taught to de-escalate,” Craig said. “There are points in the video where certainly it appeared that did not happen. If someone’s back (is) to you and you’re still continuing to use hard hands, that is a concern.”

Craig said the woman was treated for minor injuries after the incident.

Authorities continue to investigate.