Chowdhury was injured in the September ambush, while his driver was killed, said freedom fighter Mahbubul Alam, who was part of the mission.
After the verdict on Wednesday, he said the operation had proved Chowdhury’s claim of being outside the country in 1971 false.
The International Crimes Tribunal-1 sentenced Chowdhury to death on Oct 1, 2013 for murdering Kundeshwari Oushadhalaya owner Nutan Chandra Singha, genocide of Hindus at Sultanpur and Unsattar Parha.
He was also convicted for the abduction and murder of Hathazari Awami League leader Sheikh Mujaffar and his son Sheikh Alamgir.
The Appellate Division confirmed the ICT verdict after the BNP leader challenged it.
“This is why we had decided to kill him.”
He said the mission at the end of September was unsuccessful as Chowdhury’s driver, instead of him, had died.
Freedom fighter Kazi Nurul Absar was among the members of the mission.
He, too, testified before the tribunal.
“We were unsuccessful that day but we now want his swift execution,” Alam said.
He said he went to testify before the tribunal to prove wrong claims of Chowdhury’s lawyers that he was not in the country during the Liberation War.
“Three incidents proved his presence in the country,” he said.
Absar wanted the Goods Hill house to be made museum to remind people of the torture on freedom fighters.