Migration information service Mediendienst Integration asked all 16 state police agencies, the Federal Criminal Police (BKA), the Federal Police and the Office for the Protection of the Constitution about their workers' origins.
Most states do not collect figures on the backgrounds of their entire police forces, and neither do the federal agencies.
In the states which do record such figures, numbers were low.
Lower Saxony reported that 3.2 percent of police officers were from migrant backgrounds, Rhineland-Palatinate had 2.5 percent and Mecklenburg-Vorpommern just 0.4 percent.
The levels of people with migrant backgrounds in those states are 17.8 percent, 19.6 percent and 3.8 percent respectively.
However, advertising campaigns aimed at encouraging more applicants from migrant backgrounds were successful in Berlin and Lower Saxony. Since 2013, both states have received applications proportionate to the numbers in the population at large.
But similar campaigns in Hesse, North Rhine-Westphalia, Hamburg and Schleswig-Holstein didn't achieve the same success.
The Office for the Protection of the Constitution, meanwhile, makes no special effort to attract applicants from a migrant background and does not collect statistics about its employees' origins in most states.
But four of its state offices do. The state of Brandenburg claimed “no-one” came from a migrant background among its officers. In Hamburg the figure was 2.7 percent, Hesse was 5.2 percent and Lower Saxony 4.1 percent.
And the federal police and BKA, while running a targeted campaign to recruit people from a migrant background, also do not collect statistics.
The investigation was prompted by the investigation into the “National Socialist Underground” (NSU) case, which revealed massive gaps in police understanding of people from migrant backgrounds.
The NSU carried out ten killings between 2000 and 2007, targeting immigrants and a policewoman. Investigators took years to pick up their trail because they didn't consider the possibility that the murders had a racist motive.
One of the recommendations of the special parliamentary committee appointed to investigate the failures was that the police do more to recruit people from migrant families.
“The NSU terrorism experience shows that the security authorities have a serious lack of intercultural sensitivity,” Green Party interior affairs expert and former policewoman Irene Mihalic said.
“That's true of the federal police and the Federal Criminal Police too,” she said. “Leaders desperately need to do more.”
Wolfgang Schönwald, spokesman for police union GdP, said in a statement that “the first results show that we're on the right path, even if the impact could be much greater”.
“We shouldn't be thinking in terms of quotas or anything like that...we have to bring more people with a migrant background closer to our job.”
Rainer Wendt, head of the German Police Union (DPolG) claimed that the police are already doing everything they can to recruit more officers with a migrant background.