Odds are you own some sort of phone with a rechargable lithium-ion battery, possibly from companies like Samsung, Microsoft and Apple. Those batteries are in a lot of things you might own these days, including hybrid and pure electric cars.

According to a recent report from Amnesty International, a key ingredient in these batteries, cobalt, is often supplied by firms that use child slave laborers in the Democratic Republic of the Congo.

Mark Dummett is a business and human rights researcher at Amnesty International and he wrote a report on this discovery. He speaks with A Martinez about the topic.