It had already existed for years, as shown by the riots among fans of SG Dynamo Schwerin during a match between the two teams in 1968. The disapproval was kept in check as long as the club was relatively unsuccessful, but complaints increased and feelings became inflamed as the club grew successful. A turning point was the fractious encounter between BFC Dynamo and Dynamo Dresden in Dresden in December 1978, which ended with unrest at the Rudolf-Harbig-Stadion, with 35 to 38 fans of both teams arrested. BFC Dynamo won the match 2–1. Hans Modrow, then SED First secretary in Bezirk Dresden, blamed the unrest on "inept officiating", and there were accusations from Dresden that manipulation of the match was "yet another form of discrimination against the city". The privileges of BFC Dynamo and its overbearing success in the 1980s made fans of opposing teams easily aroused as to what they saw as manipulation by bent referees, especially in Saxon cities such as Dresden and Leipzig. Petitions to authorities were written by citizens, fans of other teams and local members of the SED, claiming referee bias and outright match fixing in favor of BFC Dynamo. Animosity towards the club had been growing since its first league titles. The team was met at away matches with aggression and shouts such as "Bent champions!" or ”Stasi swine!”. Fans of BFC Dynamo would even be taunted by fans of opposing teams with "Jews Berlin!". Complaints due to alleged referee bias accumulated in the mid-1980s. As a consequence the German Football Association of the GDR (DFV), under its General Secretary Karl Zimmermann, commissioned a secret study on the problems with referee performance and behavior in relation to the matches involving BFC Dynamo, Dynamo Dresden and 1. FC Lokomotive Leipzig in the 1984–85 season. The study came to the conclusion that BFC Dynamo was favored and had gained at least 8 points due to alleged referee bias. The study found several referees that had allegedly favored BFC Dynamo in matches. The study found a direct advantage of BFC Dynamo in ten matches and a disadvantage of its two closest competitors, Dynamo Dresden and 1. FC Lokomotive Leipzig, in eight matches together. The study showed that 45 yellow cards had been handed out to Dynamo Dresden and 36 to 1. FC Lokomotive Leipzig, compared to 16 yellow cards for BFC Dynamo, and that yellow cards had been handed out to key players in Dynamo Dresden and 1.