The victim Sukhram Lalchu Wadde (35) was a member of Naxal militia, who had surrendered before the police in July 2016, a senior police official said.
The Naxals attacked Sukhram at Kehakavi village and murdered him using an axe, he said.
"The Maoists were angry as Sukhram had turned himself in before the police," the official added.
He said last week three villagers were killed allegedly by Naxalites in Aheri and Korchi tehsils in Gadchiroli.