The police said the body of 25-year-old Ramapada Kamilla bore marks of multiple injury and was found from Balibasti village at Sonachura after he went missing Thursday evening.
The incident comes a day after the all-party meeting convened to restore peace at Nandigram ended abruptly.
The Trinamool Congress-backed 'Bhumi Ucched Pratirodh Committee' claimed Kamilla to be its member and alleged that he was killed by the CPI(M).
The body was sent for post-mortem at Tamluk, police said.
Meanwhile, intermittent firing and bomb blasts were reported from CPI(M) strongholds of Tekhalibazar and Bhangabera areas since last evening.
Police said the firing stopped only this morning.
Committee sources alleging that the CPI(M) has stepped up violence and one of their members, Khokan Das Adhikary, was assaulted by them on Thursday.
Nandigram Block-I BDO Ashok Sarkar said that Adhikary had complained to him about the CPI(M) assault on him.