Union’s President Dirk Zingler late on Monday severed the sponsorship deal that would have given the club €10 million over five years with International Sport Promotion (ISP) after news magazine Der Spiegel revealed that the company’s supervisory chairman Jürgen Czilinsky had served at the East German Ministry for State Security.

The club leadership made clear this was incompatible with Union’s famous anti-authoritarian reputation in communist East Germany and that it was terminating its contract with ISP because Czilinsky did not disclose his past.

“Further cooperation under these conditions, even taking into consideration the legal and economic consequences for the club, wasn’t possible,” Zingler told the Berliner Morgenpost on Tuesday.

During the Union’s time in the East German league, it had an intense rivalry with Dynamo Berlin, which counted the country’s state security minister, Erich Mielke, as its chairman. The Stasi chief used his power to make sure the team was stacked with the best players the now defunct German Democratic Republic had to offer, resulting in 10 league titles from 1979 to 1988. After the country collapsed in 1989 officials found that many of those titles were aided by bribed referees and fishy player transfers.

As a result of their anti-Stasi reputation, 1.FC Union developed an anti-establishment fan base and became a tolerated, unofficial opposition in the communist state. Fans sang tunes that were thinly-veiled attacks on the East German authorities while the club never finished higher than seventh place in the league.

Since joining a reunified German football league (DFL), Union had financial woes, twice losing out on opportunities to move into a higher level of play because of money problems, however, the club’s supervisory chairman Antonio Hurtado said this week’s decision was about the fans and not a business decision.

“The club’s leadership cannot be diverted from its former path – that has always been our guarantee for success,” he said.

Union are currently leading the Bundesliga’s second division after being promoted last season.

But unless a comparable sponsor can be found quickly, the Union may have to scale back its proposed €12.2 million budget. It also had plans to pay off an estimated €15 million debt incurred by renovations to its beloved Alte Försterei stadium.

The DFL still has to approve the team’s decision.

The sponsor affair is an unwanted distraction from its excellent start to season. The Berlin team squares off against football giants Bayern Munich in a friendly match on Wednesday evening.

ISP is registered with the Chamber of Commerce in Dubai and is part of umbrella company ISO International Development and Consulting GmbH, which has an office in Berlin. Its business includes environmental management, raw material developments as well as renewable energy technology.