Montu, one of the organisers of the Liberation War, breathed his last at Square Hospital around 5 pm, said Gonoforum publicity and publication secretary Muhammad Ullah Modhu.
He said the Gonoforum leader was admitted to the hospital recently with lung infections.
Montu was involved in Bangladesh Awami League politics from his student life and was elected president of Jubo League, the youth wing of the Awami League. He also served as the general secretary of Awami League's Dhaka City unit.
He was elected an MP from the Dhaka-3 constituency as an Awami League candidate during the third parliamentary election in 1986.
In the fifth parliamentary election in 1991, he contested the polls again from Dhaka-3 with an Awami League ticket but was defeated.
Montu was expelled from the Awami League in 1992 and joined Gonoforum when Dr Kamal Hossain founded the party in 1993, reports UNB.