Khaleda Zia’s lawyer said he would appeal in the Supreme Court, in a final attempt to stop the trial.
Bangladesh’s High Court has sentenced the son of the country’s main opposition leader to seven years in prison for money laundering.
The decision against 51-year old Tarique Rahman was handed down on Thursday by a two-member bench.
The High Court overturned a 2013 acquittal, in which a Dhaka court had cleared Rahman of charges that he and a friend siphoned off millions of dollars to Singapore between 2003 and 2007.
“The High Court said Tarique Rahman influenced political power to help his close friend, Giasuddin Mamun, to get and then launder 200 million taka ($2.5m),” Deputy Attorney General Moniruzzaman Kabir told AFP news agency.
“Mamun took the money as a bribe for securing a power plant contract for a construction company and laundered the money to a Singapore account,” he added.
Rahman will now be barred from politics unless the Supreme Court overturns his conviction, Kabir said.
Defence lawyer Zainul Abedin said that, in addition to his prison sentence, Rahman was fined $2.5m.
Abedin said his team have not decided if they will appeal to the Supreme Court.
Rahman, who lives in London, is the eldest son of Khaleda Zia, opposition leader and two-times former prime minister.
He is the senior vice chairman of Zia’s Bangladesh Nationalist Party (BNP), and was considered Zia’s political heir apparent.
The high court’s conviction could put an end to Rahman’s political career.
There was no immediate comment from the party after the sentence was announced.
Rahman’s sentence is the most recent challenge facing the BNP.
Bangladeshi politics has been strained for years in rivalry between current Prime Minister Sheikh Hasina and Zia.
Both women are related to former national leaders, and have alternated as prime minister for the better part of the past two decades.
The BNP’s decision to boycott the controversial 2008 elections weakened the party, as did the following crackdowns on the opposition carried out by Hasina’s government.
In March, a Bangladeshi court issued an arrest warrant for Zia over a deadly fire-bomb attack that had taken place last year.
The opposition leader was also charged with sedition early this year, and other members of the BNP say they have been harassed and forced to flee the country.