The verdict from the top appeals court on Tuesday now means that there is now no legal bar to executing his death sentence for the abduction, torture and killing of teenage freedom fighter Jasim Uddin Ahmed during Bangladesh’s nine-month War of Independence from Pakistan.
The development has left the pro-Pakistan Al-Badr militia commander of 1971 with the option to seek president's mercy by repenting for his crimes.
The five-strong Appellate Division bench headed by Chief Justice Surendra Kumar Sinha delivered the verdict Tuesday morning.
Mir Quasem is the sixth war criminal to see the verdict at its execution level and the fifth top Jamaat leader whose death sentence for war crimes has been upheld in the final verdict.
Before him, death-row war criminals Motiur Rahman Nizami, Ali Ahsan Mohammad Mujahid, Md Kamaruzzaman and Abdul Quader Molla and BNP leader Salauddin Quader Chowdhuyr had filed review petition and failed to overturn their sentences.
In line with Article 49 of the Constitution, any convict can seek pardon from the president as the last option to dodge the death penalty. Mir Quasem now will have the same chance.
But the government will execute the sentence if he does not seek clemency or the president rejects his plea.
An official of the Supreme Court Registrar's Office said the court will publish the full review verdict after all the judges sign it. Then it will be published on the Supreme Court's website too.
Then three copies of the verdict will be sent to the International Crimes Tribunal (ICT), which sentenced Mir Quasem to death in November 2014, the jail authorities and the district magistrate of Dhaka.
Two more copies will also be sent to the home ministry and the counsels of both the State and defence.
The 63-year-old war criminal is currently in a condemned cell at Gazipur's Kashimpur prison.
After receiving the verdict's copy, the ICT will order the prison authorities to take necessary steps following the judgment.
Once the ICT judges who had delivered the original verdict sign it, three copies will be sent to the jail authorities, the district magistrate and the home and law ministries.
Then prison officials will read out the verdict to Mir Quasem and ask whether he would seek presidential clemency.
Regarding the course after that, Attorney General Mahbubey Alam said, "If he (Quasem) files the mercy petition, it will be sent to the president. Then the process will follow the president's decision."
"It will be a different matter if the president pardons him. If not, then the process to execute him will begin. And if (he) does not seek mercy at all, he can be executed any time."
In that case, the government will decide when Mir Quasem will be executed.
However, his family will be allowed to meet him in jail for the last time before the execution. But the sentence will not be carried out until the mercy petition issue is resolved.
The whole process will be set into motion once the full review verdict is published, said the attorney general.
President Md Abdul Hamid is currently in London for eye treatment and medical check-up. He is scheduled to return home on Sep 4.
Asked whether the authorities will have to wait until Sep 4 for the president's return, Mahbubey Alam said, "The president can be notified about this wherever he is staying. There is no problem about that."