The accused couple, Siyanand and Sangita, have been taken into custody and are being interrogated on the matter, they said.
The incident took place on February 2 when the victim, Golu, went missing from his house. The locals claim they heard his cries, but later could not trace him, they said.
The minor's body was recovered from a field located in Rali Chauhan village yesterday, they said.
According to a preliminary report, the boy was strangulated by a rope and several bones near his cervical spine were also found to be broken.
The investigation is underway in the matter, police said.