The case, which was initially registered by the Vadakadu police as a suspicious death under Section 194 of the Bharatiya Nagarik Suraksha Sanhita (BNSS), has now been altered to include murder and relevant sections of the Protection of Children from Sexual Offences (POCSO) Act.

The victim, a Class 4 student and the son of an agricultural daily wage worker, was found dead near a pond about 100 metres from his house in Karukkakurichi village late on June 27 night. The boy, who had gone out to play with friends around 6.30 pm, was discovered with injury marks on his neck and face, and was found without his trousers.

According to the police, a team of investigators inspected the crime scene with the help of a sniffer dog. A breakthrough was achieved on June 28 morning, when children who had been playing with the victim informed investigators that the 17-year-old suspect, who is from the same area, had taken the younger boy away shortly before his disappearance.

Based on the information, the police picked up the teenager for questioning.

"During the course of the investigation, the boy confessed that he had tried to make sexual advances towards the nine-year-old. When the child resisted and tried to escape, he strangled him with a cloth and murdered him," a police source said.

The minor accused was subsequently lodged in a home for juveniles in conflict with the law on Monday morning.