The incident was a serious human rights violation and the NHRC would be approached soon, Citizen Rights Preservation Committee General Secretary Sadhan Purkayastha told reporters here.
Arjun Namasudra (32) had allegedly committed suicide on June 8 after he was declared a 'D' or doubtful voter and was not given the form for a voter photo identity card.
"Namasudra was an Indian but was tagged as a 'D' voter. It is clearly a case of human rights violation," Purkayastha said.
He claimed that the man was was a poor daily wage labourer and could not manage the legal expenses and became depressed.
Namasudra was a resident of Indo-Bangla border village Haritikar part-I (Subodh Nagar colony) under Katigorah police station.
He had hanged himself to death after a case was filed against him in the Foreigners' Tribunal alleging he was a doubtful citizen.