'Inspection of the scene suggests that he was murdered inside the ruins and then his body was dragged outside so that it could be seen by passers-by in the morning. The assailants would have first tried to choke him to death before inflicting knife injuries on him,' said a police officer.

'It seems that the kidnappers killed the boy for fear of being arrested. Investigations and search are under way to arrest them,' said a police officer.

The body was taken to the All Indian Institute of Medical Sciences (AIIMS) for a post-mortem examination and was later handed over to his family. Ribhu was cremated later in the evening.

The grieving family, still in a state of shock, refused to speak to the media while one of the relatives accused police of inaction and inability.

'Police did not do anything. It's police's fault... they were given the car registration number and still they failed to trace it. Had they shown some seriousness, our child would have been saved,' said one of the relatives, refusing to be named.

K.R. Mangalam School principal Lily Mathew described Ribhu as an average student.

'Till Wednesday morning we were not aware about his abduction. We got to know (about it) in the morning when we called up his house inquiring about his absence. We were told that he was kidnapped,' Mathew told reporters.

Police suspect an insider's hand. 'We suspect the involvement of someone known to the family. We are probing the matter from all possible angles,' the official added.

Police have also asked the school to provide them a list of those students who had passed in past two years.