Bundesliga teams are some of the least financially transparent in Europe: "German clubs are really a black box in terms of transparency"

German football is on the forefront of pushing for financial sustainability but when looking at financial transparency they are decades behind other big European leagues.

Only four Bundesliga clubs publish their financial reports on their websites. The rest point to the DFL's annual financial overview with only a few selected key figures.

UEFA's club licensing regulations require clubs to publish their last audited financial information.

Neither UEFA nor the DFL are willing to answer questions on the lack of disclosure, criticised by accounting and auditing professor.