The family members of the student, identified as Tushar, have, however, alleged foul play behind the death.
Police said the Tushar's body was found on Thursday morning at 11 a.m. by some students inside the toilet of Jeevan Jyoti Senior Secondary School in Karawal Nagar.
Tushar was a student of Class 9. "He was rushed to a nearby private hospital, where he was declared brought dead," a senior police officer said.

"During preliminary investigation, there were no visible injuries marks found on his body. However, the deceased's family members alleged foul play and said he was beaten up by some students inside the school's toilet," he said.
"We have registered a case of culpable homicide not amounting to murder against unknown persons," the police officer said, adding they are waiting for the postmortem report to ascertain the cause of death.
According to the school management, Tushar was allegedly suffering from diarrhoea, which led to his death.
"Some students were seen entering toilet after Tushar in the CCTV footage, we are questioning with those students. A probe is on," an official added.