OAKLAND PARK, Fla. – A South Florida man was arrested last week after he beat his girlfriend’s 4-year-old son and injured the boy’s penis, authorities said.

According to an arrest report, Mohammad Mahmoud Shaar, 26, of Coconut Creek, dropped off his girlfriend at her workplace in Oakland Park Feb. 13 before taking her son to a babysitter’s home.

The boy became increasingly upset as his mother was getting out of the car, the report stated.

Broward Sheriff’s Office deputies said the babysitter’s home was only 1.6 miles away from the mother’s place of work, but Shaar took 20 minutes to get there.

The babysitter told deputies the child was crying hysterically and shaking when he arrived, but Shaar left immediately without giving her any explanation about what happened.

She said the boy told her “Mo did it to him,” the arrest report stated.

According to the arrest report, the babysitter took video and photos of the child’s injuries, which included red marks on his face, neck, ears and back.

She then called the boy’s mother, who went to her home with another woman to see the injuries for herself.

Deputies said the mother called Shaar, but he claimed that he didn’t harm her son and that he loves the boy like his own child.

The mother and the other woman returned to work as the babysitter took the boy to a church function, authorities said.

The babysitter noticed bruising and a cut on the boy’s penis when he went to the bathroom at the event, the report stated.

“Mo did it,” authorities said the boy told his babysitter.

According to the report, the babysitter had initially thought the boy had defecated in his pants because of the way he was walking, but it was actually because of the pain he was in.

The woman again contacted the boy’s mother and they took him to Broward Health Medical Center to be treated for his injuries.

Authorities said the boy was interviewed by detectives and demonstrated how he was hit in a slapping motion by his mother’s boyfriend.

“The victim also stated that the defendant pulled his penis and with a clenched jaw and tight fist, exhibited the way in which he was forcibly grabbed in the penile region,” the report stated.

The boy said he was cut on his genitals by the suspect’s nails, authorities said.

According to the report, Shaar denied abusing the boy and claimed that the redness to his back was because the child was choking, so Shaar patted him on the back.

He said it was possible that his hand struck the boy’s neck, face and ears during the incident, but that he did not intend to harm the boy, authorities said.

Detectives said Shaar denied touching the boy’s penis and claimed that the boy grabbed himself in that area during the car ride because he had to use the bathroom.

Detectives said it was implausible to believe that the boy caused the injuries to himself.

Shaar was arrested on a charge of aggravated child abuse and was taken to the Broward County Main Jail.