Humayun was elected to parliament from
Narsingdi-4 in
2008 and
2014 as a candidate of the
Bangladesh Awami League. He was the chairperson of both the Parliamentary Standing Committee on
Ministry of Commerce (Bangladesh) and of
Ministry of Expatriates Welfare and Overseas Employment. In January 2019, he was appointed the Minister of Industries. Humayun lost his ministerial and Jatiya Sangsad membership positions after the fall of
the Sheikh Hasina led government in August 2024. Subsequently, he was arrested by a team of the
Rapid Action Battalion on 25 September 2024 and sent to jail by a Narsingdi court; he was charged of a murder Jahangir Alam, a Sramik Dal leader, in Narsingdi on 4 August during
the quota reform movement. On 8 April 2025, the
Anti-Corruption Commission (ACC) filed two separate cases against Humayun and his wife, Nadira Mahmud, over allegations of illegally acquiring wealth amounting to BDT 9.28 crore. ==Death==