But the party has announced no new agitation to protest against the final verdict.
Chowdhury was sentenced to death by a special tribunal on Oct 1, 2013 for murdering Kundeshwari Oushadhalaya owner Nutan Chandra Singha, genocide of Hindus at Sultanpur and Unsattar Parha, and abduction and murder of a Hathazari Awami League leader and his son.
The Appellate Division upheld the tribunal’s verdict on Wednesday after a year and nine months.
“We believe Salauddin Quader has been denied justice,” BNP spokesperson Asaduzzaman Ripon said at a media call at the party’s headquarters.
“He has been sentenced to death unfairly.”
Chowdhury, who terrorised Chittagong during the 1971 Liberation War, is the fifth to get a verdict on the appeal against the tribunal’s judgment.
“We’re frustrated, surprised and saddened at the verdict,” Ripon added.
Chowdhury, who began his political career with the Muslim League, switched many parties before finally settling in the BNP in the mid-90s.
He is now a Standing Committee member of the party.
The six-time MP from Chittagong told officials at the Kashimpur jail where he is currently lodged that he would seek a review of the verdict.
He told the jailor he was innocent and a “victim of political vendetta”.
About three million people were killed and millions of others displaced and forced to seek refuge in India during the nine-month war.
The Awami League-led government formed a tribunal to try war crimes suspects in 2010.
Most of those convicted are from the BNP’s ally Jamaat-e-Islami, which opposed Bangladesh’s independence.
The party claims the tribunals fall short of international standards and accuses the government of wreaking political vengeance on the opposition – a charge the government fiercely denies.
Chowdhury, a minister under military strongman HM Ershad, is the second former minister to have been given death penalty for war crimes.
The BNP has always kept mum on the convictions of Jamaat leaders on war crimes charges. Party chief Khaleda Zia initially dubbed the trials a ‘farce’ but has since avoided talking about war crimes issues.
BNP spokesperson Ripon said the party was optimistic that the Appellate Division would consider Chowdhury’s review appeal.
“That’s why we are not announcing fresh agitations,” he said replying to a question.