Plot: Panorama investigates the African migrant trade and reveals the extraordinary scale of people-smuggling across sub-Saharan Africa - a multibillion-pound industry described by some as a new 'slave trade'. As theEU desperately tries to cut the number of migrants crossing the Mediterranean, reporter Benjamin Zand investigates how hundreds of millions of euros of EU funding is being spent and asks if EU efforts to tackle the smugglers could be leaving some migrants in an ever more dangerous limbo