Perhaps it's ok with flag to talk about political poems here. I'm linking a very powerful political poem by Ken Sara-Wiwa. He was murdered by the Nigerian government for activism against the oil development that was destroying the lands of his tribe. It's called "The True Prison".
I recall reading the defence speech that Saro-Wiwa gave at a Nigerian military court. Your description of the case is as I remembered it to the word. It's a very permanent story and one that's worth looking into.