Majumder contested the controversial by-election in Mirpur on 3 February 1993. He lost the election to Bangladesh Nationalist Party candidate Sayed Muhammad Mohsin. He was arrested in August 2002 by
Bangladesh Police during the
Bangladesh Nationalist Party government.
Amnesty International feared that he would be tortured in custody. Majumder was elected to Parliament in the
2008 Bangladeshi general election, beating Bangladesh Nationalist Party candidate
Muhammad Hamidullah Khan. On 22 October 2013 his car was attacked with Molotov cocktails outside Mohona TV. He was elected to Parliament in the General Election 2014 as a candidate of Bangladesh Awami League from
Dhaka-15. He beat his nearest rival Ekhlas Uddin Molla, an independent candidate by 26,786 votes. Majumder is the chairman of
Mohona TV, a private television channel. He is a member of the Parliamentary standing committee on Housing and Public Works Ministry. On 19 October 2024, a Dhaka court placed him on a three-day remand in connection with the killing of student Ikramul Haque. Ikramul had sustained bullet injuries on 4 August during the student-led
mass uprising and later died at the
Combined Military Hospital on 14 August. Chief Metropolitan Magistrate Judge Ali Haider passed the remand order after the investigation officer requested a seven-day remand. Kamal was arrested by police from
Gulshan in the early hours of 18 October. Ikramul's father, Ziaul Haque, had filed a murder case on 7 September with Shah Ali police station. ==Personal life==