The Fourth Special Court on Wednesday sentenced former jute and textiles minister Shajahan Siraj, his wife Rabeya Siraj and their son Rajib Siraj to eight years' imprisonment each in connection with two offences of tax evasion. Meanwhile, Metropolitan Special Tribunal-12 sentenced detained Dhaka City Corporation Ward Commissioner Chowdhury Alam to 10 years' rigorous imprisonment in connection with extorting Tk 20 lakh from a market owner in August 2003.