Henry Crimes is charged with child abuse after the incident at Paxon Middle School, where his son is in the seventh grade, WJXT-TV, Jacksonville, reported Wednesday.
The police report said the boy suffered a large cut above his eye, a swollen arm and bruises, and was shaking when officers arrived. The boy has since been taken into state protective custody, the report said.
Crimes told investigators he had been called by his son's gym teacher, Aaron Jackson, who told him to bring a belt to deal with misbehavior.
"Coach Jackson sent a child with his key to open the door so I could beat my child for misbehaving," Crimes' police interview transcript says. "I hit my son with the belt about twice and he fell down. I told him to get up. When he got up, I hit him some more, then he fell again ... then I made him go to Coach Jackson to apologize."
Jackson has been removed from the classroom as deputies and education officials investigate, the report said.