Bayern Munich have launched a complaint to UEFA about the way their fans were treated by Spanish police in the 4-2 loss to Real Madrid at the Bernabeu.
The German giants have released a statement on their official website confirming the action they are taking and have requested a report from the Spanish authorities, detailing what they feel happened in the stadium.
A statement on the Bundesliga club's website read, as per Mirror: "During half-time of FC Bayern's Champions League match at Real Madrid on Tuesday, there were violent attacks by Spanish police against FC Bayern Munich fans.
"FC Bayern find the Spanish police's actions misplaced and excessive.
"FC Bayern have already filed a complaint with UEFA against the actions of the Spanish police. In addition FC Bayern will request a statement about the actions from the Spanish police."
It is the second time in a week that the Spanish authorities have come under scrutiny after they clashed with Leicester fans last week before their match against Atletico - some of the scenes on social media were not pretty.
As well as the actions of the Spanish police, Bayern Munich manager Carlo Ancelotti has the right to feel poorly treated by the match officials after a hugely controversial affair against Los Blancos.
Two of Cristiano Ronaldo's three goals were found to be offside while Arturo Vidal received a second yellow card for a perfectly clean tackle on Marco Asensio, a decision which effectively decided the outcome of the match.
It was not a good night for Bayern and it remains to be seen what action will be taken against the Spanish police.