Ministers have said there is no evidence asylum seekers were involved in the violence.

But the leaked police report, published in Bild newspaper and Spiegel, a news magazine, claims that one of those involved told officers: “I am Syrian. You have to treat me kindly. Mrs Merkel invited me.”

Another tore up his residence permit before the eyes of police, and told them: “You can’t do anything to me, I can get a new one tomorrow.”

A local newspaper reported that fifteen asylum-seekers from Syria and Afghanistan were briefly held by police on New Year’s Eve in connection with the sex attacks but were released.