The victim's family has alleged that the boy was killed by their distant relatives.
The boy had gone missing on Friday and his body was found late Sunday.
According to a villager, who had spotted the body, the child had injury marks all over the body.
Police are waiting for the post-mortem report to ascertain the exact cause of death.
According to the police, an FIR has been registered against three relatives and two unknown persons under section 359 (kidnapping) and section 302 (murder) of the IPC. One of the accused has been arrested.
Superintendent of police, Manoj Kumar Sonkar, said, "Initial investigation revealed that the brother of the child's mother had earlier murdered his wife. The child was targeted by the deceased woman's relatives to extract revenge. One of the accused has been arrested. He is being interrogated to get more details. A special team has been constituted to arrest the other two accused."