MADELEINE McCANN: THE HUNT FOR THE PRIME SUSPECT

Three year- old Madeleine McCann disappeared without trace from her parents holiday apartment in Portugal 13 years ago. It's a mystery that has gripped the world. Now German prosecutors say they believe they have a prime suspect, a convicted sex offender who was living near the apartments at the time. But 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.