Nationalist Prime Minister Viktor Orban's government in May announced the special tax measure targeting "extra profits" earned by major banks, energy companies and other firms, aiming to plug budget holes created by a spending spree that helped him gain re-election in April.
"The consumer protection authority has found a breach of the law today because the airline (Ryanair) has misled customers with its unfair business practice," Justice Minister Judit Varga said in a Facebook post on Monday.
"Ryanair ... will immediately appeal any baseless fine raised by the Hungarian Consumer Protection Agency," the email said. "No notice of any such fine has yet been received by Ryanair. If necessary, Ryanair will appeal this matter to the EU courts."
The new levy on involves a tax worth 10 to 25 euros on passengers departing Hungary from July.
Ryanair had previously called on Orban's government to scrap what it called a "misguided" tax, saying the measure would damage Hungarian tourism and the economy. read more
Ryanair, which has also taken issue with the tax being levied on a loss-making industry, said it would be forced to move growth capacity to countries that were working to restore traffic in the aftermath of the coronavirus pandemic.
Orban's taxes on "extra" profits at banks, insurers, large retail chains, the energy industry, telecoms companies and airlines is reminiscent of the tax regime he used to fix the budget after he swept to power in 2010.
Reporting by Gergely Szakacs; Additional reporting by Anita Komuves; Editing by Bradley Perrett and David Holmes