The incident took place around 7 pm yesterday when the boy, Babu, was standing near the house after a bath and his mother had gone to bring his clothes, they said.
The police said that when the mother returned, the boy was missing.
She immediately alerted her husband Musharaff Ali, a worker at the estate, and his co-workers. They launched a search for the boy, they said.
The estate workers have been asked to stay indoors after dark by forest officials, who are taking steps to trace the leopard and trap it, they said.