In the report, the Mayor of Amsterdam blamed Ajax hooligans for stirring the violence that erupted in the capital last month.
The city's police force said the Dam Square rioting was triggered when three Ajax supporters stole a flag from a group of Celtic fans.
City mayor Eberhard van der Laan said that incident, and a 'hit-and-run' raid on a bar packed with travelling fans the night before, were the main spur for the violence on November 6.
In a letter to the city council he wrote: "I interpret this hooligan behaviour as possibly the most important cause for the emergence of disorder between the Celtic supporters and the Amsterdam police at Dam Square."
Five Celtic fans are appealing against prison sentences for using violence against police. They say the officers who arrested them failed to identify themselves and accused the police of brutality.
Celtic have submitted a dossier of 25 complaints by fans to a Dutch lawyer who is deciding whether to press charges against police.
Mr Van der Laan asked police to submit a report to the council on the half-hour on Dam Square that led to the arrest of 28 Celtic fans and 17 Ajax supporters. It said Celtic fans had been in Dam Square since the morning and were drinking heavily, but had been on good terms with the police.
Police said the flashpoint came when the three Ajax fans snatched the flag and ran off. As police tried to arrest the Ajax fans they came under attack from travelling supporters, according to the report by police chief Jan Pronker.
The report said: "The challenging attitude and violence on the part of the Celtic fans towards the police was unexpected in terms of its origin, development and scale. This did not conform to the 'good reputation' of these supporters."
The mayor said "all necessary measures were taken by police in their preparations and focussed on preventing escalation".
Jeanette Findlay of fans' group Celtic Trust said: "This letter, and the 'investigation' on which it is based, is no more than a cover-up of the brutal and criminal behaviour of the Dutch police.
"We find it incredible the Dutch authorities have allowed the police to investigate themselves in this matter and even more incredible that their elected representatives find this letter acceptable. We continue to protest the innocence of our fans who did not receive a trial as we would understand it.
"We hope there will be criminal charges brought against members of the Dutch police and compensation received for brutal treatment meted out to numerous Celtic supporters on that night."
Padraig Mullen, 28, and 23-year-old Damian Dobbin, from Hamilton, received jail sentences of two months at the District Court in Amsterdam on November 22.
Thomas Kennedy, 30, and Andy Vance, 21, were sentenced to six weeks and Joseph McPherson, 20, were given a one-month sentence. All were released and returned home pending an appeal. A sixth man, John Quigley, was acquitted.