Wolfgang Albers, 60, was put into "temporary retirement," said national news agency DPA as well as the city newspaper Koelner Stadt-Anzeiger, quoting unnamed local government sources.
Police have recorded more than 120 complaints by women of assaults ranging from groping to two rapes, allegedly committed in a large crowd of revellers during year-end festivities outside the city's main train station and its famed Gothic cathedral.
The attacks were carried out despite a heavy police deployment in the western German city, and officers have admitted that they did not realise what was happening.