The cocaine trade generates billions of dollars for criminal gangs right around the world but most of the supply of the drug comes from Colombia. Some the money made in this illegal economy does filter into the legal one and by some estimates the cocaine business now accounts for 4% of Colombian gross domestic product.

How does the cocaine business generate so much money and for who? We also ask what would happen in places like Colombia if the world legalised the cocaine trade, if it could be taxed and revenue earned by Governments much in the same way as products like tobacco and alcohol. We hear from a former Colombian president and Nobel Prize winner who says it should.

Presenter/producer: Gideon Long

(Image: Coca plants. Credit: Getty Images)