Madeline McCann: The Hunt for the Prime Suspect

Three-year-old Madeleine McCann disappeared without trace from her parents’ holiday apartment in Portugal in 2007 – it’s a mystery that has gripped the world, but now German prosecutors say they believe they have a prime suspect, a convicted sex offender who was living near the apartments at the time. Who is Christian B., and why has it taken a decade for him to be linked to the crime? Julie Etchingham investigates a trail that has involved police forces from at least three European countries.