Authorities today served the death warrant to 72-year-old Nizami, two months after the apex court upheld his death penalty.
"We received the death warrant earlier this morning and served it to the convict (in the death row)," an official of the suburban high security Kashimpur Jail briefly told reporters.
Attorney general Mahbubey Alam, meanwhile, said the top leader of the country's biggest Islamist party would now get 15 days time to seek review of the judgement by the Supreme Court itself in his final bid to evade the gallows.
He, however, said that the scope of reviewing the judgement in a war crimes case is very slim. "If he prefers not to get the judgement reviewed within the time-frame or if his petition is rejected, the government may execute the verdict anytime in the subsequent days," Alam told newsmen.
He said Nizami, however, could seek presidential mercy immediately if the review petition was rejected but he would not get any extra time to decide for seeking the clemency.
Bangladesh's International Crimes Tribunal (ICT-BD) originally sentenced Nizami to death in October 29, 2014.
The apex court upheld the verdict on January 6 this year. According to TV reports Nizami's lawyers sought to meet their client in jail as the death warrant was issued to know his mind if he wants to exhaust the opportunity of filing a review petition.
Leader of infamous Al-Badr force in 1971, Nizami is the last remaining top perpetrators of crimes against humanity whose fate now hangs on the balance.
Nizami was found guilty of systematic killings of more than 450 people alone in his own village home in northwester Pabna siding with the Pakistani troops during the liberation war.
Nizami at that time was the chief of the student front of Jamaat, which was opposed to Bangladesh's 1971 independence.
Four opposition politicians, including three leaders of the Islamist party, the Jamaat-e-Islami, have been convicted by a war crimes tribunal and executed since late 2013.
Two others -- former Jamaat chief Ghulam Azam and ex-BNP minister Abdul Alim --- earlier were handed down "imprisonment until death" penalty instead of capital punishment due to their old age as they exceeded 80. They subsequently died in the prison cells of a specialised state-run hospital due to old age ailments.