How can international mining companies be held accountable?

It is a familiar story, African country at war, big international company comes in search of natural resources, and then what should be a blessing to a country ends up fuelling the conflict further.

The Democratic Republic of Congo, Angola and Sierra Leone have all seen their natural resources - gold, oil, diamonds - pillaged

While there are various international voluntary agreements to try to persuade global mining companies to do business in an accountable way, there is so far not much of a legal framework to ensure that those who break the rules are prosecuted.

A debate organised by the Open Society is taking place today at the Hague on the issue, BBC Focus on Africa's Sophie Ikenye asked Gavin Hayman, a campaigner for Global Witness, how effective such a framework would be.