Your dad is in prison - From Anonymous

Please don't print my name and keep me anonymous. I have a problem with my son as he is being bullied at school because his dad is in prison. His dad has been sent down for drug dealing. Me and his dad had split up last year because of drugs and since his name and address was put in our local newspaper, my son has been going through hell at school and is bullied every day. 
I can't seem to find any help and the teachers at my sons school have been very good but the bullying is still happening and my son is becoming withdrawn.
His dad and other offenders don't realise what affect this has on their families when they go down that road and his dad doesn't seem to care. My son does write to him and speaks to his dad on the phone because he misses him and its his dad. The newspaper opened a comment thread and there was very nasty comments left on it and my son found out. Its not his fault but he is taking the flack for his dads ill behaviour. Has anyone else gone through this? From Anonymous.