COLUMBUS, Ga. -- A 13-year-old Georgia student had his leg amputated after he was body slammed several times by a school contract worker, a lawyer said.

The boy’s mother, Lawanda Thomas, said the incident happened on Sept. 12 at the Edgewood Student Services in Columbus, Ga.

Thomas said her son, Montravious, wanted to leave the classroom but allegedly was told that he could not. That's when, she said, her son was physically assaulted by a school contract worker.

PHOTOS: Teen's leg amputated after school incident

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The family’s attorney, Renee Tucker, said that Montravious was picked up by the waist and slammed to the floor three times.

"He picked him up around his waist and body slammed him to the floor," Tucker said. "We know he attempted to leave the class a couple more times, and he was picked up two more times around his waist and body slammed to the floor."

Thomas said she noticed her son limping when he got off the bus.

“I walked out to the school bus and I asked what was wrong with him,” Thomas said. “He said the teacher slammed him.”

Thomas said her son’s knee was out of place, so he was airlifted to Children’s Healthcare of Atlanta at Egleston.

His leg was amputated on Tuesday.

Montravious will at Egleston for another at least another month for healing and rehabilitation. He’ll also learn how to walk with a prosthetic leg.

The school issued a statement saying that the person accused in the incident, Bryant Mosley, is not an employee of the Muscogee County School District, but was a contract service provider. He’s no longer providing services to the school district as an investigation is made into the incident.

The school’s full statement is as follows:

We extend our thoughts and prayers to our student who is undergoing medical treatment and to his family. We are committed to conducting a thorough review of the alleged incident at the AIM/Edgewood Student Services Center to determine all of the facts. The person involved in the alleged incident at AIM/Edgewood Student Services Center is not an employee of the Muscogee County School District. Bryant Mosley was provided by Mentoring and Behavioral Services, a contract service provider, to the Muscogee County School District. Mr. Mosley is not presently providing services to the Muscogee County School District. Mr. Mosley is specifically trained in MindSet curriculum, a system of preventing and managing aggressive behavior, and Georgia restraint requirements. It is our understanding that there were issues concerning the safety of the child and others in the room, which called for the use of restraint per state guidance. Physical restraint is allowed in Georgia public schools and educational programs in those situations in which the student is an immediate danger to himself or others and the student is not responsive to less intensive behavioral interventions including verbal directives or other de-escalation techniques.