Swiss chocolate giant Lindt & Sprüngli may lose EU trademark rights to the shape and wrapping of its popular Easter bunny line.

This follows a European Court of Justice preliminary ruling, which concluded Austrian courts could void the registration, if the trademark was filed in “bad faith”.

Specifically, the court defined “bad faith” as if Lindt trademarked the design knowing a rival firm already had in the EU “an identical or similar sign [and product]” capable of being “confused with” Lindt’s trademarked design; or if the company applied for the mark “to prevent that third party from continuing to use such a [design]”.

The company brought the case against Austrian competitor Franz Hauswirth. Lindt claimed its Easter bunny design was so similar it infringed trademark rights. Hauswirth is resisting the action, which now returns to Austria’s supreme court.