Illegal oil is big business in the Niger Delta. Oil thieves cut the pipelines, siphoning off oil, which they refine in the bush and sell on the black market. This vast underground industry is a huge employer in the region but it’s a dangerous business. Earlier this year, over 100 people were killed in an explosion at an illegal refinery.

The local government has been cracking down on the illegal oil trade. They say the business is responsible for the worryingly high levels of pollution in the Niger Delta, where a thick black smog hangs over the city of Port Harcourt and oil runs through the waterways, destroying mangroves.

BBC West Africa correspondent Mayeni Jones meets an oil thief king pin, an exuberant local politician, taking on this illegal business and treks deep into the forests of the Niger Delta to visit an underground refinery.

Presenter: Mayeni Jones