Atalanta fans are helping Eintracht Frankfurt supporters get around the ban for tonight’s Champions League tie at the Stadio Maradona, because of their bitter rivalry with Napoli.
It kicks off at 20.00 GMT and the build-up has been dominated by violent clashes in the streets of Naples.
While circa 200 Napoli ultras have tried to make contact with the Eintracht supporters, the majority of the violence has been between the German fans and police.
Several cars were set on fire and objects thrown, and again Atalanta ultras have been identified joining in with the Eintracht fans.
According to FAZ in Germany, Atalanta fans helped the Germans to get around the banning order by purchasing the tickets for them.
They are also staying with the Frankfurt supporters in the hotel and it now remains to be seen whether they will be able to enter the stadium.
The bitter rivalry intensified in 1986-87 when a bus carrying Atalanta supporters was wrecked, then revenge clashes in Bergamo in 1991-92 leading to an arrest and five injuries.
Police tried desperately to prevent Napoli and Atalanta fans coming into contact at the train station after their match in the 1996-97 season.
Banning orders failed to take effect in 2007 when Neapolitans who lived in the Bergamo area were able to gain access to the stadium and were then attacked when identified.
When Napoli recently hosted Atalanta in Serie A, only six visiting fans were present, because the vast majority of Dea supporters are based in or were born in Bergamo.