BERLIN — Germany’s top court on Wednesday dismissed an appeal by two British bankers over their conviction in a massive tax evasion case, confirming that the so-called cum-ex transactions they used were illegal.

The Federal Court of Justice also confirmed that the seizure of about 176 million euros ($208million) from Hamburg-based private bank M.M. Warburg was justified.

The ruling sets a key precedent for future trials in the “cum-ex” scandal involving hundreds of suspects.

The two British bankers had received suspended sentences after agreeing to provide detailed information about the fraud scheme, in which participants loaned each other shares to collect reimbursement for taxes they hadn’t paid.

Hundreds of bankers allegedly were involved in the scheme and reportedly defrauded taxpayers of billions of euros.