Bayern Munich have called in the police after bags of blue paint were thrown against the front of their city centre headquarters at the weekend.
Bayern have provided the authorities with CCTV footage of the attack on the building on Munich's Saebener Street in an effort to identify those responsible.
"The front of the Service Center was struck by several blue paint bags,'' Bayern said in a statement. "Therefore, FC Bayern have reported the incident to the police due to the damage of property.
"Today, the police have been provided with video recordings, in which the damage can be seen, to help them with their investigations.''
The attack is understood to have been carried out by supporters of Bayern's city rivals 1860 Munich, who play in the German second division and are on the verge of financial collapse.
1860, whose club colours are blue and white, need around £8 million to see them through until the end of the season, and Bayern's offers of financial support have not been well received by some of the club's fans.
Bayern recently purchased 1860's share in the Allianz Arena, which was a joint venture between the two clubs, and offered concessions on the running of the stadium.