Laurence Griffiths/Getty Images
Borussia Dortmund chief executive Hans-Joachim Watzke has criticized "back-door funding" of some European clubs. Dortmund are set to face Manchester City on Wednesday in the Champions League (via Daily Mail).
Fans own 51 percent of Borussia Dortmund, the two-time defending German champions. United Arab Emirates businessman Sheikh Mansour owns Manchester City, the defending English champions.
City have a 10-year, £350 million sponsorship with Etihad, a company controlled by Mansour's brother.
UEFA must find the thin line between sponsorship and excessive back-door funding – they must show strength to expel big clubs. No tycoon should be allowed to pump crazy money into a club with sponsorship from five companies he controls. If that happens, financial fair play will fail.
Watzke also said Dortmund would not take on foreign investment.