The CBI has detained a Class 11 student of Ryan International School in Gurugram in connection with the September 8 murder of a Class 2 student, official sources said on Wednesday.

According to sources in the Central Bureau of Investigation, the senior student was seen with a knife inside the school campus on the day the seven-year-old was killed with his throat slit in a school bathroom.

The detained student is suspected of having watched a pornographic clip in the morning, and on seeing Pradyuman Thakur in the school bathroom, he might have tried to sexually assault him when he entered it, minutes after he was dropped by his father.

The student will now be produced before the Juvenile Justice Board in the afternoon, where the court is expected to decide whether he is to be treated as a major or a minor as per the Juvenile Justice (Care and Protection of Children) Act, 2015.

The Haryana Police had afterwards claimed that Pradyuman was killed by school bus conductor Ashok Kumar inside the toilet as the boy resisted a bid to sodomise him.

While Kumar has been arrested, Pradyuman's parents and two other staffers have claimed that he was being made a scapegoat.