The individuals arrested in Ukraine, a man in his 40s and a woman, are accused, among other things, of attempting to gather intelligence on the location of air defense systems in Transcarpathia, which borders Hungary and has a significant Hungarian minority.
"For the first time in Ukraine's history, the security service has exposed a Hungarian military intelligence network that conducted espionage activities," SBU writes in a statement on Friday.
Former soldiers
The individuals arrested have previously been Ukrainian soldiers and were led by a Hungarian intelligence officer, according to SBU. They risk life imprisonment. The intelligence officer is suspected of having provided the individuals with cash and having attempted to recruit additional individuals to the network.
The purpose was also to gather information on the local population's stance, not least in the event of a hypothetical scenario where Hungarian soldiers entered the region.
Hungary's Foreign Minister Péter Szijjártó calls the accusations "anti-Hungarian propaganda", without directly denying them.
I urge everyone to be cautious with news published in Ukrainian propaganda outlets. If we receive any details or official information, we can handle it then, he says.
On good terms with Putin
On Friday afternoon, Szijjártó announced that two Ukrainian diplomats had been expelled from Hungary.
Today, we expelled two spies from Hungary who worked under diplomatic cover at Ukraine's embassy in Budapest, he says in a video clip on Facebook.
A few hours later, Ukraine responded by doing the same.
"Two Hungarian diplomats must leave our country within 48 hours", writes Ukraine's Foreign Minister Andrij Sybiha on X and adds that it concerns "the principle of reciprocity and our national interests".
Hungary is opposed to Ukraine's potential EU membership and has argued that EU support to Ukraine should be lifted. The country has also argued that the sanctions against Russia should be lifted. At the same time, it is well-known that Prime Minister Viktor Orbán is on relatively good terms with Russia's President Vladimir Putin.