The results were leaked before the study was finished, Christian Pfeiffer, director of the Institute for Criminology Research in Lower Saxony, told Friday's edition of the regional daily paper Rheinischen Post. Researchers still had not completed 18,000 of the 50,000 interviews planned with students around Germany.
"They could still make a big difference in the results," Pfeiffer said, calling the leaked results an "dubious distortion" of the facts.
The leaked survey showed almost a third of all German schoolchildren agreed "completely" with the statement that there are too many foreigners in Germany. Another third of those asked "mostly" agreed.
Almost a fifth of the 9th grade children included in the survey also had open prejudices against Islam, and one out of every 13 admitted to committing a hate crime like spraying a swastika on a wall or damaging the property of foreigners.
The report by a nationwide committee working to combat youth violence was prepared for Thursday's conference of German state interior ministers and was leaked by the regional daily paper Neue Osnabrücker Zeitung.