Three teenaged boys allegedly kidnapped their 14-year-old friend for ransom to buy a computer to play games but instead strangled him to death after feeding him rosogulla and cold drinks, the police said.
The incident took place in Krishnanagar's Ghurni area in West Bengal's Nadia district.
The body, tied in a sack, was recovered from a pond in Hijuli area on the outskirts of Krishnanagar city on Saturday.
The police nabbed the trio and produced them before a juvenile court in Krishnanagar on Sunday.
"The deceased, a resident of Ghurni and a class 8 student, had gone missing on Friday afternoon while going to a nearby shop to buy some items. His mother received a ransom call of Rs 3 lakh on Saturday morning, following which she informed the Kotwali police station.
"We nabbed the trio, who are class 10 students of the same school the deceased studied in and are also local residents. They confessed to killing the boy and dumping his body in a pond," a police officer said, adding further investigation is underway to ascertain the motive behind the murder.
The police, however, suspect that the trio realised that the boy's mother may not be able to pay the ransom amount and killed him fearing they will be caught by the law enforcers if they released him.
The body has been sent for post-mortem examination, he said.
According to local sources, the deceased's father had died long ago and his mother works as an 'aaya' (caregiver), while the mother-son duo stayed at their maternal uncle's house.