As Britain has grown into a nation of coffee lovers, Starbucks and Nespresso have become two of the world's biggest coffee brands. They have revolutionised what people drink and how they consume it. On the back of their success, both firms make bold claims about how their beans are ethically sourced and, in particular, that child labour is not used in their supply chains. But in this investigation, Dispatches travelled to Guatemala and discovered young children working long hours in gruelling conditions to pick coffee beans that supply these two coffee giants. Reporter Antony Barnett hears how a day's work can earn the children little more than the price of a Starbucks latte or a pack of Nespresso pods