Jatiyatabadi Swechcha-sebak Dal President Shafiul Bari Babu died at a hospital in Dhaka early yesterday.
He was 51, according to family sources.
"He breathed his last at 4am at Evercare Hospital while undergoing treatment for lung infection and breathing problems," Abdul Quader Bhuiyan Jewel, general secretary of the organisation, told The Daily Star.
Babu, a former student leader, was admitted to Anwer Khan Modern Hospital on Monday afternoon and later shifted to Evercare Hospital at 1:52am as his condition deteriorated.
He left behind his wife, a son, daughter and a host of well-wishers to mourn his death.
Babu was a former student of Dhaka University's marketing department and also general secretary of Jatiyatabadi Chhatra Dal.
He was buried at his family graveyard in Laxmipur's Ramgati after Asr prayers, following a second namaz-e-janaza.
BNP acting Chairman Tarique Rahman and BNP Secretary General Mirza Fakhrul Islam Alamgir expressed shock at his death.
His first janaza was held in front of BNP's Nayapaltan central office, attended by many party leaders and activists. After the janaza, Fakhrul paid last respect to Babu, on behalf of the party, by placing a wreath at his coffin.