Police have turned their investigations towards the 'witnesses' of the fabricated attack.
German newspaper Bild has issued a retraction over its 6 February 2017 story claiming that a marauding group of up to 900 drunk migrants and refugees ran rampant though an upmarket area of the city committing sexual assaults.
“They took me under the skirt, between my legs, my breasts, everywhere. Me and my girlfriends. More and more of these guys came. Their hands were everywhere,” the discredited article quoted one woman as saying.
But police have said there is no substance to the claims, and have begun investigating the ‘witnesses’ for false claims about a criminal offence.
“There were no massive mob attacks by masses of refugees,” local police said in a statement.
Extensive investigations by police have shown the accusations to be “untenable and without foundation.”
“The inspections of all emergency calls and mission logs of the night showed no evidence of the criminal offenses and the alleged mobs,” police said.
After questioning witnesses, police said they had considerable doubts about their credibility, with one alleged victim not even the city at the time.
Bild has issued an apology and removed the original article from their website – but not before the story was rehashed by websites such as Breitbart.
“It is with regret that the editorial staff has to say that the reported statements and allegations of the alleged victims are in no way confirmed by the police and are completely unreliable,” editors wrote.
They said a waitress, a restaurant manager and two of his staff mislead the newspaper.
Police said they are continuing to investigate those behind the hoax and may seek to recover investigation costs from them.
The hoax came a year after Cologne’s New Year's celebrations which saw about 1000 men attack women in the city square.
Police received more than 100 complaints, including two allegations of rape.
At the time, police chief Wolfgang Albers said witnesses and women who reported being attacked described the men involved as looking as if they were from "the Arab or North African region".
Germany is facing an election later this year and migration and refugees are expected to feature prominently in debates.