A.T.M Azharul Islam, 62, became the 16th person and the 11th Islamist to be convicted of atrocities by the International Crimes Tribunal, which found him guilty of being a key member of a militia.
Azharul Islam is the assistant secretary general of the nation’s largest religious party, the Jamaat-i-Islami.
He was ordered “hanged by the neck” for the genocide in the northern district of Rangpur. “No doubt, it was mass murder,” presiding judge Enayetur Rahim told a packed court.
The nine-month war in 1972 saw what was then east Pakistan break away from the regime in Islamabad.
Prime Minister Sheikh Hasina created the controversial tribunal, a domestic court with no international or United Nations oversight, in 2010.
It has mostly focused on the trials of the Jamaat leaders who opposed the break-up of Pakistan and saw the liberation war by Bengalis as a conspiracy by India.
The tribunal has also sentenced to death a former minister of the main opposition Bangladesh Nationalist Party.
Defence lawyer Tajul Islam rejected the charges against Azharul Islam and said his team planned to appeal the verdict in the Supreme Court.
“Azharul Islam was a 19-year-old student during the war and in no way was involved in war crime. The charges against him are false and fabricated,” the lawyer said.
Previous death sentences handed down against Jamaat leaders, including its supreme and spiritual leaders, plunged Bangladesh into its deadliest unrest last year.
Thousands of Islamists clashed with police in nationwide protests over the verdicts and other issues that left some 500 people dead.
The BNP and Jamaat have called the trials politically motivated, aimed at eliminating opposition leaders rather than rendering justice. Rights groups have said they fall short of international standards.
The government maintains they are needed to heal the wounds of the war, which it says left three million people dead.
Independent researchers put the toll much lower.