The German Boxing Board have joined the British Boxing Board of Control in condemning the decision to allow David Haye and Dereck Chisora to fight in July.
The contest, which is due to take place at West Ham United's Upton Park, has been sanctioned by the Luxembourg Boxing Federation.
However, neither boxer has a valid boxing licence with the BBBofC - something that has provoked a negative reaction from their German counterparts.
"I was surprised, disappointed, upset and shocked when I heard [about the] fight between Dereck Chisora and David Haye," said BDB president Thomas Putz.
"Neither Chisora or Haye hold a valid licence with the BBBofC."
The BDB have also written to the European Boxing Union to voice their concerns.