It is every parent's nightmare. Ever since their four-year-old daughter went missing from a holiday resort in Portugal's Algarve region on May 3, Gerry and Kate McCann have launched a high profile campaign to find Madeleine, who was allegedly abducted from the bedroom of the villa where they stayed. The British couple, who are doctors, had left her and her two-year-old twin siblings, who were unharmed, in the apartment, while they went to a restaurant on the premises.

They have already met Pope Benedict XVI in Rome and traveled to Madrid, which was the start of their tour of European capitals to raise awareness for their daughter's disappearance.

Now they have publicized their appeal in Germany since German and Dutch tourists make up the majority of foreign tourists in Algarve.

Publicizing appeal in Germany

"We are here to ask the German public for help in searching for our little daughter," Gerry McCann announced at a press conference in Berlin with his wife Kate at his side.

The couple asked German tourists to look through holiday photographs taken in Portugal last month to see whether the little girl, and perhaps also her abductor, might be in the background. When a journalist suggested that they could in some way be involved in the abduction of their child, Gerry McCann retorted: "I have never heard before that anyone considers us suspects in this and the Portuguese police certainly don't."

The case has captured considerable attention from the German media. Bild, the mass circulation tabloid, published an open letter to the McCanns from Brigitta Sirny, the mother of the Austrian girl Natascha Kampusch, who had been kidnapped as a 10-year-old on her way to school and held in captivity for more than eight years. Last summer, Kampusch made a dramatic escape from her abductor, who then killed himself before he could be arrested.

Parallels with abduction of Austrian girl last year

"My daughter Natascha was also kidnapped," Sirny wrote. "She was held for 3,096 days at the mercy of a demented criminal. I have suffered countless hours of despair. Hours in which I kept asking myself: Why? Why my child? Who has done this? Who would kidnap a defenseless child? Could I have stopped it? Did a lapse of a few minutes cost years of my child's life?"

The newspaper also quoted Sirny as saying that publicizing the case, which became a sensation in Germany, was the right thing to do, "because the worst that could

happen for a kidnapped child is to be forgotten."

There is still hope

In an interview with German newspaper Berliner Morgenpost on Sunday, Gerry McCann said that there was still hope.

"As long as there is hope, we are not giving up," he said. Kate McCann said she hoped Madeleine was safe and was being cared for.

"We know there are evil people out there, but there are also confused people," she said. "We do not know who this person is. We hope the latter."

The couple also met with the mayor of Berlin, Klaus Wowereit. They said they would fly to Amsterdam later Wednesday to make a similar appeal there.