S. Thakur, the Balrapur superintendent of police, said Sunday that Bahadur Kudako, 25, confessed to the crime.
The nun´s body was found in the Chalgali forest on Nov. 27. An autopsy confirmed that she had been raped before being killed, the Indian Express reported.
Police said that Sister Sarita Toppo had gone to collect firewood with another nun on Nov. 27.
Thakur said that Kudako admitted assaulting the nun after finding her alone in the forest. Kudako told the police that he lost his temper when the victim threatened to inform the villagers about the assault. He then attacked her with an ax.
Ambikapur Bishop Patras Minj said that such "incidents are very grave, especially when the victim of such a heinous crime is working for the well-being of the whole of humanity."
He demanded adequate security measures for missionaries working in remote parts of the state.