Clinging to hope their daughter is alive, Kate and Gerry McCann have launched a 24-hour hotline to find her.
The line was to be manned on a confidential basis and people were encouraged to ring in with sightings or evidence.
A spokesman for the couple, Clarence Mitchell, said: "Without any hard evidence of her death, Kate and Gerry hope against hope that she is alive.
"They want this to exist as another line for anybody who might want to contact somebody independently.
"Any credible leads, of course, will be acted upon."
Portuguese and Spanish police had given the McCanns their full backing in setting up the number, which was to be based in Spain.
The operators of the line will speak a range of languages, including Spanish, Portuguese, Arabic, French and English.
In a heartfelt appeal on Spanish television, the McCanns were expected to urge people to phone + 34 902 300213 if they have any information about the missing girl.
They were concentrating on north Africa and the Iberian Peninsula because it is thought to be the area where the little girl is "most likely" to be.
The McCanns' spokesman denied the hotline had been set up simply for a need to use the money donated by the public to the Find Madeleine fund.
"We would not be doing it if we did not think it would work," he said.
"It would be a foolish waste of the generously donated money."
Mitchell added that the hotline does not indicate the McCanns have lost faith in the Portuguese investigation.
He said the couple welcomed the "fresh approach" generated by a change in the police head overseeing the case.