On February 2, when the girl was sitting alone in the class room of Naveen Government Primary School at Lato village here, the guest teacher - Prem Kumar (22) - asked her to go to the toilet for cleaning her running nose, police said.
The accused then followed the girl and after reaching the toilet locked its door and allegedly raped her, Sub-Divisional Officer of Police (SDOP) R F Kalda told reporters.
After reaching home, the victim informed about the offence to her grandmother, following which she approached the police yesterday and filed an FIR in this regard.
After an initial probe, police arrested Prem Kumar, the SDOP said.
The victim was initially admitted to the Mandla District Hospital, but when her condition deteriorated she was referred to Jabalpur Government Medical College.