Argentina link in Madeleine search

It is understood a mysterious call claiming to know the whereabouts of the four-year-old came from a mobile phone registered in Argentina.

The "credible" call was considered so potentially significant that the McCanns halted their search of Europe to help police investigate.

They delayed their flight from Berlin to Amsterdam by three hours and plans were drawn up to divert to the UK.

It was thought the McCanns might need to return to Britain to talk to specialist advisers about the call.

The call from the pay-as-you-go phone came from a man who wanted to speak directly to the McCanns, according to Spanish police sources.

He did not reveal his identity or nationality, but the phone was soon linked to the South American country.

All efforts to re-establish contact with the caller failed on Wednesday and the couple carried on with their journey around Europe.

In Praia da Luz, Mr and Mrs McCann planned a trip to Morocco as the final part of their attempt to raise awareness of their daughter's disappearance.

They are keen to go because of its proximity to Portugal. Several ferries a day leave from Tarifa in Spain for the 35-minute crossing to Tangiers.