A Miami Beach police officer was caught on camera appearing to suddenly deliver a strong punch to a suspect's face, officials said Wednesday.

The police department's internal affairs unit has launched an investigation after NBC Miami aired footage that allegedly shows an encounter between 35-year-old Lowell Lavaine Poitier and police officer Adriel Dominguez, officials said.

Officers had been called to the Pelican Hotel in Miami Beach on Dec. 3 on a complaint that a man, identified in the police report as Poitier, was causing a disturbance and wouldn't leave, officials said.

The video, which is from another officer's body camera, seems to show Poitier marching around and uttering expletives before coming close to Dominguez's face and saying, "What?"

The officer then suddenly delivers a swift, powerful right hand to the left side of Poitier's face.

Officer Dominguez, in his report, justified his use of force, saying Poitier was behaving in an "aggressive manner" and had "clenched his fists" as if he were ready to attack.

"Dominguez in fear for his safety struck the [defendant] with a closed fist punch with his right hand, which made contact with the [defendant's] left side facial area," the officer wrote.

Prior to the punch, Poitier had also been calling police officers "crackers," according to the police report.

Lowell Lavaine Poitier Miami Beach Police Department

The video was provided to NBC Miami by Michael Pizzi, a lawyer who said he is representing another police officer who came forward with the footage and is seeking protection as a whistleblower.

Poitier was taken to a hospital for treatment before he was booked into custody on suspicion of assaulting a police officer, resisting an officer without violence, and disorderly conduct, the police report said. He was later released on bond.

“I was made aware of this incident this morning. This is obviously a very serious matter," according to a statement by Miami Beach Police Chief Dan Oates on Wednesday.

"At my direction, our Internal Affairs Unit immediately launched an investigation. We have also notified the Miami-Dade State Attorney’s Office. The officer has been relieved of his patrol duties. He will be placed in a non-enforcement assignment until further notice.”

The police union representing the officer said in a statement that it "fully supports and defends Officer Dominguez’s actions" against an "agitated, angry and physically aggressive defendant."

"There is no question Officer Dominguez was legally justified and fully entitled to protect himself," the Miami Beach Fraternal Order of Police said. "We are confident that a fair and thorough investigation will result in Officer Dominguez being cleared of any wrong doing."