Anger is growing in Germany over suspicions of a migrant sex attack cover-up
Police and victims have furiously demanded to know why organisers did not warn them that refugees had committed abhorrent sexual harassment amid speculation such information could have helped avert the sickening attacks on New Year's Eve.
Young women had to flee the welcome event in terror after being groped by gangs of migrant men, even though organisers repeatedly interrupted the music with messages in Arabic urging them to stop their harassment.
The revelations have raised the ugly prospect that some of those refugees were free to go on and commit the twisted sex crimes on New Year's Eve because politically correct council officials did not report them to the police.
Angela Merkel's government is under increasing pressure to come clean over the true numbers of sex crimes linked to migrants after it emerged that authorities deliberately withheld the nationalities of the Cologne attackers for several days.
They also "covered up" similar incidents in other cities including Dusseldorf and Hamburg, Munich and Berlin.
Angela Merkel has come under pressure to expose the true level of sex crimes committed by migrants
There has been a heavy police presence in Cologne since the New Year's Eve attacks
Today the council official responsible for the integration of refugees in the Cologne region admitted organisers knew about the sex attacks at the event but did not want to make a fuss.
She also shockingly said she "cannot remember" whether she advised the women who were attacked to go to the police, but added she felt the event's student organisers "had learned from the situation".
The appalling incident, on November 7, 2015, only became known of at all because one of the victims bravely decided to go to the police in the aftermath of the Cologne sex attacks.
She told the city's Express newspaper how she and her friend were surrounded by migrants at the party, which was held on a boat, and were repeatedly groped despite asking the men to stop.
I'd only been there a few minutes, and I got the first hand on my breast
Sex attack victim
She said: "I guess there were about 100 to 150 asylum seeker men there. I'd only been there a few minutes, and I got the first hand on my breast."
Soon the fondling increased even further until there were "up to four men were pressing themselves on me and my friend at the same time", according to the victim.
She said one migrant then grabbed her and kissed her, at which point she managed to break free and run off with another friend.
The Cologne police force today furiously demanded to know why it was not alerted to the crimes by the organisers, even though the situation was so bad they had to make repeated pleas to the migrant men to stop sexually harassing young women.
Police have offered a 10,000 euro reward for information about the attackers
A sign in a shop window asks 'do you feel safe' and offers CS gas for sale
Critics have asked whether police could have done more to prevent the Cologne attacks
North Rhine-Westphalia region police spokesman Robert Scholten said: "The music had to be constantly stopped so that the message could be given out in Arabic to stop men harassing female guests.
"We could have been called at this point but nobody alerted us to the problem."
But the council official responsible for integration matters, Coletta Manemann, who helped organise the 'Refugees Welcome' event, did not report the incidents and has now been accused of a cover-up attempt.
Admitting that she knew about the incident "shortly before Christmas" after talking to students who had been assigned to helping the refugees, she said: "I can't remember any more if I told them that they needed to go to the police or not."
Amazingly she said she later concluded that "the student organisers had learned from the situation" and felt there was no need to make a fuss.
Supporters of the far-right AfD party have marched in protest against the sex attacks
German politicians debated boosting police numbers to reassure the public in light of the attacks
However since then police have taken statements from numerous women who confirmed they had been sexually assaulted.
The ship party took place in the city of Bonn, which is the same administrative region as Cologne where 1,000 migrant men would later go on the rampage, raping and robbing young women out celebrating New Year's Eve.
Ms Manemann insisted that the the shocking incident was different to those attacks, dismissing any suggestion that a complaint might have warned police what was going to happen.
But the revelations will spark huge concerns that politically correct authorities in Germany are deliberately burying bad news about migrants, meaning the police do not know the full scale of the threat they face.
In a statement the local council said it was standing by Ms Manemann, with mayor Ashok Sridharan insisting: "She has an extremely difficult job to do, and could not have realised what dimension the events that happened at the party could have taken."
The fallout from the Cologne attacks continued to hit Germany today, with officials in another city revealing they had to cancel a planned carnival because of fears of a Cologne-style attack on visitors.
Organisers of the Rose Monday carnival parade, in Rheinberg near Dortmund, said the event was being axed "for security reasons" linked to the horrific events on New Year's Eve.
A refugee camp housing several hundred people, many of whom are North African, has been established just outside the city.
Earlier this week it emerged that police are investigating the theory that many of the Cologne attackers may have been Moroccan criminals who entered Germany illegally posing as Syrian refugees.
Prosecutors are offering a 10,000 euro reward for any information about the perpetrators as Angela Merkel looks to toughen her stance amid devastating criticism of her open door immigration policy.