because it didn't want to reveal its sources of funding.

George Soros Joshua Roberts | Bloomberg | Getty Images

As it pulls up stakes and makes an exit from Hungary, George Soros' philanthropic organization called the latest accusations from that country's government about the pullout "nonsense."

Without providing specifics, Hungary's Foreign Affairs and Trade Minister Peter Szijjarto told CNBC Thursday that Soros' Open Societies Foundation (OSF) left the country because it didn't want to reveal its sources of funding. In response to Szijjarto's accusation, OSF Chief Communications Officer Laura Silber told CNBC in an email, "That is nonsense." She said the foundation's departure took place "because, in the words of our President Patrick Gaspard: 'The government of Hungary has denigrated and misrepresented our work and repressed civil society for the sake of political gain, using tactics unprecedented in the history of the European Union.'" The announced departure of Soros' non-governmental organization (NGO) from Hungary in May made headlines amid an outcry from advocacy groups that the country's government is cracking down on civil liberties. Its staff have been relocated to Berlin. OSF representatives said that they were no longer able to keep their staff safe under the government of Prime Minister Viktor Orban, and that they were a target of government surveillance.

'A threat to national security'

But Szijjarto has other ideas about the group, arguing that organizations like the OSF, which advocates for migrants' rights and resettlement, threaten national security. "I have my own thought why they left," the minister said while at the annual Organization for Economic Cooperation and Development (OECD) forum in Paris. "They left because they didn't want to publish whom they are financed by ... I'm pretty sure that they have things to hide."

A billboard with a poster of Hungarian-American billionaire and philanthropist George Soros with the lettering 'National consultation about the Soros' plan - Don't let it pass without any words' is seen in the 22nd district of Budapest on October 16, 2017, as the conservative government prepares their new national consultation. Attila Kisbenedek | AFP | Getty Images

Still, the minister lacked specifics, admitting, "I don't know why they're hiding their financial resources, but the fact is that they want to hide them." He added that only a minority of the country's NGOs have complained about strict new laws mandating the disclosure of funding sources, saying that this was telling in itself. Silber responded by pointing out that the organizations the OSF funds in Hungary are publicly available on the foundation's website, and that the OSF's funding is provided by George Soros.

Long-running hostilities

The current government of Hungary has long been in open conflict with Hungarian-born Soros, who has donated billions of dollars to notably liberal causes. Soros, a Jewish survivor of the Nazi occupation, is a staunch advocate of immigrant rights, which has put him directly at odds with Hungary's right-wing government. "Hungary has national security interests," Szijjarto said. "One of them is to be able to protect the border, to be able to control who is entering the territory of the country, and to stop the flow of illegal migration." The country of nearly 10 million has quietly closed its doors to nearly all asylum seekers, and announced in February it would allow in only two asylum seekers per day. Human rights activists claim this violates international laws.

'Stop Soros'

Unapologetic in its anti-migration stance, Hungary's current administration is led by the firebrand Orban, who soundly won reelection in April to become the country's third-longest serving prime minister. Orban ran on a pledge to protect the country's borders and beef up security, while promising a "Stop Soros" bill that would heavily tax and restrict foreign-funded NGOs in the country, like the ones belonging to Soros.

Viktor Orban, Hungary's prime minister, pauses as he delivers a speech during a public ceremony in Budapest, Hungary, on Thursday, March 15, 2018. Akos Stiller | Bloomberg via Getty Images

Amnesty International has called the bill a "muzzle" on NGOs working with migrants and EU officials have expressed concern at what they view as suppression of civil society. Last summer, Soros lauded the "courageous way Hungarians have resisted the deception and corruption of the mafia state Orban has established." Orban called it a "declaration of war," accusing Soros of leading a mafia-like network. Orban critics label the government as xenophobic, and often attribute its anti-Soros campaign to anti-Semitism or an attempt to distract the public from political corruption. Szijjarto has denied this, stressing the need for outsiders to respect Hungary's security needs.

A 'totally different vision about Europe'