Hello, my name is Nal, daughter of Ken Zarawewa, and this is the BBC World Service.

Some of you will know his name, some of you might not.

If you do, then you'll know him for his actions as a poet and a protester, a man killed

for his beliefs.

If you don't know him, then listen closely.

Listen to his words, the words of my father, secret words, smuggled from his prison cell.

And here, now at last, shared with the world.

Keep out of prison, he wrote, don't get arrested anymore.

But while the land is ravaged and our pure air poisoned, when streams choke with pollution,

silence would be prison.

One of the 27 poems and two years of letters my father wrote to an Irish nun in the run-up

to his execution in November 1995.

Smuggled out of the military detention centre in breadbarskids, they're the last testament

of a man who gave everything he had for a struggle for justice.

For years, Shell Oil, with the backing of the Nigerian government, drilled for oil

in the mangrove swamps of the Niger Delta.

The pollution that followed destroyed farms and rivers and contaminated the fishing and

drinking water of the Ogoni people.

A UN Environment Assessment report in 2011 stated that,

Control and Maintenance of Oilfield Infrastructure in Ogoni land has been and remains inadequate.

The Shell Petroleum Development Company's own procedures have not been applied, creating

public health and safety issues, and the UN described the effects on the mangrove swamps

...