A Class 11 student from Gurugram’s Ryan International School was detained on Wednesday in connection with the murder of the Class 2 student inside a toilet on the campus on September 8, India Today reported. The Central Bureau of Investigation will demand custody of the student, the agency said.

“After a thorough investigation based on scientific evidence including inspection of the scene of crime, forensic analysis and an analysis of CCTV and call records, CBI apprehended the student,” CBI spokesperson Abhishek Dayal told ANI.

The Class 2 student was found with his throat slit inside the toilet. An autopsy revealed injuries on the boy’s neck, inflicted by a sharp-edged weapon, were the cause of death. A bus conductor was arrested later that day for attacking him. There are allegations against the Ryan Group school of violating security norms.

The father of the Class 11 student confirmed his son was detained, but told India Today there was a conspiracy to frame his son. He said his son was the first one to spot the Class 2 boy on the day of the murder, and that the CBI questioned him for an entire day before detaining him.

Details of whether the conductor, Ashok Kumar, was involved are not known yet. After Kumar’s arrest, the police had said he confessed to the crime, News18 reported. Kumar is still in judicial custody, The Hindu reported.