First, how old is your child? I only ask because sometimes younger children make up stories or exagerate the truth beyond reason. I would talk to other parents to see if their children have said similar stories.
But remember, as much as it may be made up, it could be true. In that case you need to take this seriously and speak to an administrator immediantly.
This is my experiences and really happened in my family. It happen since May, 2012. My daugher was 4 and she told me that she was hit by her preschool teacher. I called social services. Social services said I should believe my daughter and they suggest me to call the police. I did. I went to police station. After I done the police report, things start getting strange. 1) Someone collecting toy guns and put them in front of our front door. 2) some people who we don't know come to my front door at midnight putting hands in my mail box. Looks like trying to get my mails. 3) someone who I don't know sneaking around my front door -those are recorded by my home security camera . 3) Someone starting spreading rumors to my friends about my daugher and said how bad she is 4) Someone starting spreading rumors to my neightbors about me and said that I am crazy so don't believe what I say. 5) Someone who I know stating giving me suggestion about " Not mention anything related to the school and my daugher ". 6) Someone who I first met in my neightbor told me that the preschool where we send my daughter to might have SPECIAL BACKGROUND. So,stop mention anything about your child being hit in that school. Am I got threatning ?