Hacking (representational image) Photograph:( Reuters )
According to reports, phones monitored in Hungary included those of two investigative journalists, the owner of a news site critical of the government, an opposition mayor and several lawyers.
Hungary denied media reports on Monday that it used secret software to infiltrate the smartphones of investigative journalists and other public figures.
"The government has no knowledge of this type of data collection," Foreign Minister Peter Szijjarto told a press conference, adding that Hungary's civilian intelligence agency did not use the Pegasus software "in any way".
Media reports on Sunday claimed governments in several countries around the world had used spyware technology developed by Israel-based NSO Group to infiltrate the smartphones of potentially tens of thousands of people.
Hungary was the only EU country named on a list of leaked telephone numbers.
According to the reports, phones monitored in Hungary included those of two investigative journalists, the owner of a news site critical of the government, an opposition mayor and several lawyers.
Janos Stummer of the opposition Jobbik party, who serves as head of the parliamentary National Security Committee, demanded "consequences".
Stummer sought to convene the committee to question intelligence chiefs, and Szijjarto said the secret service head would attend the meeting if called.
The committee's vice-president Janos Halasz, a member of Orban's ruling Fidesz that has a majority on the committee, said however that the body did not need to meet.
The "left-wing" press reports were "unfounded", said Halasz.
The National Association of Hungarian Journalists (MUOSZ) said it was "shocked" by the revelations.
"If this is the case, it is unacceptable, outrageous and illegal, full information must be disclosed to the public immediately," the association said in a statement.
The reports "bring shame to the country", said Budapest mayor Gergely Karacsony, who hopes to run against Orban at a general election next year.