A Bangladeshi court on Thursday sentenced the younger son of former prime minister Khaleda Zia to six years in prison for laundering nearly $1 million through bank accounts in Singapore, a lawyer said. Arafat Rahman Koko, who was tried in absentia and is currently in Bangkok, was fined $5.2 million for the crimes, carried out when his mother was last in power between 2001 and 2006, said state lawyer Mosharaf Hossain. \"The court has convicted Arafat Rahman Koko and given him six years\' imprisonment... for earning money illegally and laundering money through Singapore,\" Hossain, who represented the government in the case, told AFP. \"He will be arrested when he gets back from Bangkok or -- as there is an agreement between Thailand and Bangladesh -- there is the possibility the government will begin extradition proceedings against him,\" he added. The court also sentenced Ismail Hossain Saimon, son of a former shipping minister and a co-accused in the case, to six years in prison and the same fine, Hossain said, adding that Saimon is currently on the run. Analysts said the verdict could trigger street demonstrations by Zia\'s Bangladesh Nationalist Party (BNP) and its Islamist allies, who have dismissed the charges against Koko as politically motivated. The BNP has recently staged protests against the government\'s plan to scrap a system of holding national elections under a neutral caretaker administration. Koko was frequently referred to as one of the most powerful men in Bangladesh when his mother was prime minister for her second term from 2001 to 2006. Zia\'s Bangladesh Nationalist Party (BNP) suffered a crushing defeat in elections in December to her bitter rival and current Prime Minister Sheikh Hasina. Both women were charged with corruption during the regime of a 2007 to 2009 army-backed caretaker government, and each spent a year behind bars only to be released as part of deals to ensure they took part in the election. Zia\'s eldest son, Tareque Rahman, also faces a string of corruption charges. He is currently living in London.