Mr. Ryan claimed the notice was made in an effort to create leverage in the dispute. Mr. Herzog denied that there was any connection between the letter and the Black Irish trademark dispute. He also said no action had been taken on those other trademarks.
Alexander Klett, a partner at Reed Smith LLP and an expert in E.U. trademark law who is not involved in the case, said that such disputes were “quite common” and that Ms. Carey’s case was “kind of stuck.”
“The only thing you really do is you can file a trademark yourself which she has obviously done,” he said. “But that trademark application has a later filing date and therefore is a weaker right, compared to the older pre-existing trademark of the Irish company.”
Mr. Ryan said that while the dispute had brought his company a headache, it had also brought publicity. “I did a search for Mariah Carey about a week ago,” he said. “In the Google image search, for a matter of about half an hour, I came up first. I said, ‘My parents will be proud.’”
Mr. Ryan said his company’s drink, although not Irish cream liqueur, was also bound up in national identity.
“Quite literally, we’re Irish,” Mr. Ryan said. “So we called it Irish because it is predominantly Irish whiskey. And we called it Black Irish because it is black. The liquid is black. And it is Irish.”
Ms. Carey’s product is available in the United States, alongside the liquor brands of other celebrities such as the actors George Clooney and Ryan Reynolds, the model Kendall Jenner and the boxer Conor McGregor, who sold his brand of whiskey in March for $300 million.