In 2015 German Chancellor Angela Merkel opened Germany up to one million third world migrants.
Seventy percent of the migrants entering Europe were men.
German officials later admitted they were not able to fingerprint all of the new migrants flooding across the border.
On New Year’s Eve a horde of young Muslim men sexually assaulted and harassed hundreds of German women outside of Cologne’s busy main train station during public celebrations.
The German women, several who were underage, were sexually assaulted and robbed by migrants.
Police in Germany will have to rethink their tactics following attacks on women in the city of Cologne on New Year’s Eve, a senior official has said.
Ralf Jaeger, interior minister for North Rhine-Westphalia, said police had to “adjust” to the fact that groups of men had attacked women en masse.
Three suspects had been identified, he said, but no arrests had been made.
Scores of women say they were robbed or sexually assaulted by men, reportedly of Arab or North African appearance.
Mr Jaeger also warned that anti-immigrant groups were trying to use the attacks to stir up hatred against refugees.
“What happens on the right-wing platforms and in chatrooms is at least as awful as the acts of those assaulting the women,” he said. “This is poisoning the climate of our society.”