That is what the Prison Service and the BBC are doing.
This man is a convicted murderer and should not be allowed to publicise his hate from anywhere, never mind a prison cell. That rule should be for all inmates, btw, not this individual alone.
Communications with all prisoners, by whatever medium, should be monitored, restricted, and in some cases banned (censored). These people have been involved in activities necessitating their removal from decent society and yet this individual is allowed to produce and export from his prison cell audio tapes the content of which would get him arrested if he were on the outside.
This, to me, shows how afraid the authorities are of the fifth column in our midst.