“We don't see any chance of finding Katharina. That's the point where we have to stop,” Markus Zimmermann, the director of the area's catastrophe protection office, told the Bild am Sonntag newspaper.
The girl was walking with her mother and sister the day after Christmas along Cape Arkona on the island of Rügen in the Baltic Sea, when the water-drenched earth gave way.
Her mother and sister were injured, while she disappeared altogether, and is assumed to have been buried under tonnes of rubble and mud.
Teams of volunteers and professionals vowed to find her, and used heavy machinery as well as search dogs, in sometimes atrocious conditions, but they were unable to find the girl.
Rescue experts have not ruled out that her body may have been swept out to sea.
“No one can tell us where we can find Katharina,” Zimmermann told the newspaper. “We've moved an enormous amount of clay and earth” but to no avail, he said. Rescuers had been working nearly two weeks to find the child.