The Neuss arrest followed a tip-off from Austrian authorities, said Frank Scheulen, spokesman for the LKA in the state of North Rhine-Westphalia.
However, the social stigmatization of prostitutes persists and many prostitutes continue to lead a double life.
Authorities consider the common exploitation of women from Eastern Europe to be the main problem associated with the occupation.
A spokesman for the German interior ministry said the German Interior Minister Thomas de Maiziere spoke about the case on Friday with his Austrian counterpart, Wolfgang Sobotka.
Computers, mobile telephones and data storage devices were seized in the Neuss raid, Mr Scheulen said.
Street is blocked with a wall and you are not allowed to bring a dogs in to the area.