The writer claimed that a member of the wrestling team was held down by teammates and slapped. There are also reports of inappropriate touching.
School officials promise a full investigation.
"We're going to be as transparent as we can within the laws that respect the student's right to privacy on both sides of the issue. And furthermore we will issue direct and swift, serious discipline related to the facts as we find them out," said Jill Hawk, District 155 superintendent.
So far, no charges have been filed.