LARGO — Sheriff Bob Gualtieri fired and arrested a Pinellas County jail deputy after an internal inquiry found he forced an inmate to do push-ups as punishment then kicked the inmate when he got tired.

Deputy James Moran, 57, faces a charge of simple battery, Gualtieri said during a news conference Tuesday. The inmate, 31-year-old Mario Christo, filed a complaint with the agency last week after he was released from a jail sentence for disorderly conduct and resisting an officer.

The sheriff, calling the situation "one of the stupidest things" he's ever seen, said there was no excuse for physical punishment of inmates. He added that forcing an inmate to do push-ups was also not allowed under policy.

"I'm kind of speechless on it because it is so ridiculous, and it is so outside the bounds," Gualtieri said.

PREVIOUS COVERAGE: Pinellas deputy fired after unnecessary use of force on handcuffed woman

On Jan. 11, Christo and two other inmates were throwing away kitchen trash in a trash bin, the sheriff said. A bird flew by and landed on the bin, and Christo threw it a cookie from the trash.

The toss didn't violate any rules, Gualtieri said. But Moran, who was supervising the inmates with another deputy, yelled at Christo to come over to him and told him to do 50 push-ups.

Jail surveillance video shows Christo, in yellow, drop to the ground and do about half the pushups before getting tired. He pauses in a plank position, then does a few more. Moran then walks a few steps over to Christo and kicks him in the side.

Christo said it felt as if he'd broken a rib, but he didn't tell anyone about what happened or seek medical treatment while he was in jail out of fear of retaliation, according to the sheriff. Christo, released April 17 but back in jail six days later on new burglary charges, could not be reached for comment.

Moran told internal investigators that he had told inmates to do push-ups before, Gualtieri said. The agency will investigate whether it's a standard practice within the jail.

PREVIOUS COVERAGE: Pinellas jail deputy fired for hitting inmate who uses wheelchair

Moran had worked for the agency since November 2012. Deputies booked him into the jail Tuesday morning. He was released Tuesday afternoon after meeting $500 bail.

Reached by phone, Moran declined to comment.

The other deputy who was supervising the inmates is also under internal investigation, Gualtieri said, adding that he should have immediately reported the incident.

"We don't treat people this way. We don't treat inmates this way," Gualtieri said. "It doesn't matter who they are. It doesn't matter where they are. They're still people."

Contact Kathryn Varn at kvarn@tampabay.com or (727) 893-8913. Follow @kathrynvarn.