The tech sold by Israeli firm appears to be behind possible mobile hacking of heads of state, activists and journalists.
Hungarian prosecutors have opened a probe into suspected unlawful surveillance following multiple complaints in the wake of allegations of misuse of the Israeli-made Pegasus spyware.
The Budapest Regional Investigation Prosecutor’s Office said in a statement on Thursday that the investigation would examine “the so-called Pegasus case, under the suspicion of the crime of gathering unauthorised secret information”.
“The task of the investigation is to establish the facts and to determine whether and, if so, what crime has taken place,” it added.
The probe came after an investigation published on Sunday by a coalition of media organisations claimed the Pegasus spyware made and licensed by Israeli company NSO had been used by governments in several countries around the world to infiltrate the smartphones of potentially thousands of people.
Hungary was the only European Union country listed as a potential user of the software.
The Hungarian investigative website Direkt36, part of the media consortium that published the expose, said a list of more than 300 Hungarian phone numbers suspected to have been targeted using the software included those of journalists, business people, lawyers and people critical of Prime Minister Viktor Orban’s government.
The reports did not identify the parties alleged to have deployed the spyware, but critics have long accused Orban, a self-styled “illiberal”, of undermining basic rights such as press freedoms since he assumed office in 2010.
Hungarian police said this week they had received two complaints about the alleged abuses, one from a private individual and one from a politician.
But Hungarian officials have dismissed the allegations made in the media reports, calling them “unsubstantiated”.
On Monday, Hungarian Foreign Minister Peter Szijjarto said the government was not aware of the surveillance activity reported in international media, adding that the Information Office, an intelligence agency under his supervision, had not used Pegasus.
Interior Minister Sandor Pinter said Hungary “has always acted in accordance with the law”.
Orban’s chief of staff, Gergely Gulyas, echoed Pinter’s remarks at a weekly press briefing, stating that details about Hungarian government surveillance activity were “not public information”.
“In such issues there is only one question to be examined, namely whether intelligence gathering took place lawfully or not,” he said. “We state that all secret intelligence gathering took place lawfully.”
NSO Group has also rejected the reporting by the media consortium as “full of wrong assumptions and uncorroborated theories”.
It has said Pegasus is sold only to vetted foreign governments, and only for use against “terrorism” and other serious crimes.
Pegasus is a form of malware that infects smartphones to enable the extraction of messages, photos and emails, recording of calls and secretly activating microphones.