Madeleine McCann may have been snatched to order by slave traders and sold to a rich family, detectives fear. They say she could have been smuggled by ferry into Africa after going missing in Portugal. An ex-Scotland Yard detective said: “It’s the obvious route.”

The news came as it was revealed a girl “identical” to Madeleine was seen on a key trafficking route in Morocco, looking sad and asking the man with her: “Can we see Mummy soon?” Investigators have told of fears the missing youngster was smuggled into Africa by slave traders who “snatched her to order” for a wealthy family. Gangs operating in lawless Mauritania, West Africa, regularly sell youngsters to rich Middle Eastern families.

It is not known if police probing Madeleine’s disappearance have looked at links to Mauritania, where slavery was only outlawed in 2007 – the year she vanished in the Algarve, aged three. But private detectives hired by the McCanns believe there are “strong reasons” to think she was taken to Morocco, a route into the country.