Ukraine has arrested two people who it said were part of a Hungarian spy ring gathering intelligence for a possible military incursion — the first time Kyiv has accused an EU neighbour of plotting against its interests.
The Ukrainian state security service (SBU) said on Friday that it had uncovered a spy network run by Hungary’s military intelligence to gather sensitive information on its defences and population in its western Zakarpattia region, home to about 80,000 Hungarian speakers.
A man and a woman — both military veterans with Ukrainian nationality — were detained as part of the operation, the SBU said.
The alleged network collected information on regional military defences and assessed local sentiment, including potential reactions to a Hungarian military incursion, the SBU said.
The Financial Times could not independently verify the information.
The Hungarian government dismissed the Ukrainian allegations and expelled two Ukrainian diplomats it called spies.
“Completely unfounded anti-Hungarian propaganda is often used in Ukraine,” Hungarian foreign minister Péter Szijjártó told a press conference in Budapest.
He added in a Facebook video: “We will not tolerate such constant defamation [so] today we expelled two spies working under diplomatic cover at the Ukrainian embassy in Budapest.”
The rights of ethnic Hungarians in Ukraine have been a long-standing irritant between Budapest and Kyiv, in particular about schooling in their native language. Hungarian Prime Minister Viktor Orbán, who has opposed EU military aid to Ukraine since Russia’s full-scale invasion in 2022 and maintained close relations with Russian President Vladimir Putin, had accused Kyiv of “Hungarophobia” and threatened to block the country’s EU accession over the issue.
Orbán has often said that Ukraine was merely a “buffer zone” between Russia and the rest of Europe and that Hungary had to prepare for any scenario once the war ended. But some Hungarian analysts were sceptical that Budapest had gone as far as gathering intelligence to lay the ground for a military incursion.
Figures close to Putin, such as Ukrainian oligarch Viktor Medvedchuk, who is accused of having run a Russian influence operation in Europe, have recently amplified the idea of neighbouring countries taking part in a free-for-all once the war in Ukraine is over. Medvedchuk told Russia’s Tass in February that such “historic claims” were “justified” as “some Ukrainian territories had been artificially incorporated in modern Ukraine”.
Hungary’s small far-right party Mi Hazánk (Our Homeland) last year said it would “claim” Zakarpattia in the event of Ukraine losing the war. Party leader László Toroczkai said he would promote a referendum in Zakarpattia to become a Hungarian “protectorate”.
The SBU said the person running the spy operation in Ukraine “was a career officer of Hungarian military intelligence”.
It said the spy ring was tasked with collecting “information about the military security” of the region, searching “for vulnerabilities in the region’s ground and air defence, and study[ing] the sociopolitical views of local residents”.
In particular, the alleged agents compiled information about what might happen “if Hungarian troops entered the region”.
The man who was arrested is a 40-year-old military veteran from the western Ukrainian city of Berehove, who the SBU said had been recruited by Hungary as a sleeper agent and put into “standby mode” in 2021.
He was later “activated” by his Hungarian handler in September 2024, the SBU said.
According to the SBU, the alleged agents were tasked by their handler to collect answers to questions such as: What will the military and civilians in Zakarpattia do if Hungarian troops enter the region? What weapons and military equipment are available on the black market there? How is the Hungarian population migrating within or out of the region? What military units are based in the area? How many transport and combat vehicles are there? How many law enforcement agencies operate in the region? How well are they equipped?
One agent was observed scouting the location of Ukrainian military units and an S-300 air defence system.
The SBU said the agent then travelled to Hungary to report to his supervisor, crossing the border with a document showing that he was transporting his sick father to a foreign hospital for treatment. Such documents are necessary for men leaving Ukraine while under martial law.
The agent and supervisor exchanged information for cash meant as payment and to pay off new recruits to expand the network of informants, according to the SBU. The agency said the man tried to recruit at least two people.
“By forming an agent network, foreign intelligence hoped to expand the range of information collection, including obtaining data from frontline and frontline regions,” the SBU said.
At a second meeting between the informant and his Hungarian handler in March, the Ukrainian man was given a phone “with special software for covert communication”, the SBU said.
The phone was meant to help the man securely share information with the Hungarian security services about vehicles belonging to SBU and military officials in the region, as well as information about the number of Ukrainian troops from the region who had been killed on the front lines.
The detained woman had also served in the armed forces and resigned from her unit this year, the SBU said. Her job was allegedly to inform the Hungarian intelligence service about the presence of Ukrainian aircraft and helicopters in the western part of the country, as well as detailed information about her former military unit.
The SBU said it seized several phones and other evidence from both suspects. In a video published online by the SBU, the man was seen with his face blurred and handcuffed. The Ukrainian security service shared what it said were wiretapped phone conversations between the alleged agents and their handler.
The two suspects are being held on charges of high treason and face life imprisonment with the confiscation of personal property if convicted in a court.
The SBU statement “seems too well documented for the Ukrainians to be bluffing”, said one analyst who declined to be named. “Hungarians have aimed for this for years: Ukraine falling apart as part of a Russian strategy” and be rewarded for their help with territorial gains.
