A report by the city's police force said the rioting in Dam Square 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 supp-orters 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."
But fans' group The Celtic Trust condemned the Mayor's conclusions as "a cover-up of the brutal and criminal behaviour of the Dutch police" and said they would "work to clear their good names".
Five Celtic fans are appealing against prison terms handed down by Amsterdam's district court for using violence against police.
They claim the undercover officers who arrested them failed to identify themselves and have accused the police of brutality.
Celtic have submitted a dossier of 25 comp-laints by fans to a Dutch lawyer who is deciding whether to press charges against the Amsterdam police.
Videos posted on social media showed one Celtic fan, Padraig Mullen, being dragged to the ground and kneed by a police officer in plain clothes.