According to the person recording the confrontation, it happened last week at Lake Correctional Institution near Clermont.
A large group of correctional officers can be seen gathered on the prison's lawn as an inmate narrates what he is recording with his illegal cellphone.
He claims the officers are beating up a fellow inmate.
He names the inmate, but Channel 9 is not disclosing the name because the agency has not confirmed that that is the inmate involved.
The video appears to show officers throwing repeated punches.
State Rep. Anna Eskamani, D-Orlando, said she plans to visit state prisons unannounced because of concerns such as the video.
"Are we upholding our responsibility as a state in ensuring these environments are not abusive, violent and difficult to live in?" she said.
FDOC said it has identified all the officers seen in the video but cannot publicly disclose their idendities until it completes its investigation.
The officers will not have contact with inmates during the investigation.
The inmate has been moved to another facility.
FDOC Secretary Mark Inch provided Channel 9 the following statement Sunday evening:
"This video is deeply disturbing. We have zero tolerance for officer abuse or misconduct for any reason. The actions of these individuals will not be tolerated. Our Office of Inspector General has launched an immediate investigation. All officers identified to be involved have been taken out of contact with inmates and will not be allowed to return to full duty until a thorough investigation has been completed. Those found participating in any level of abuse, or failing to properly report abuse, will be subject to administrative and criminal charges."