American congressman Paul Gosar, a Republican from Arizona, said that the left-leaning billionaire George Soros may have secretly organised August’s far-right rally Charlottesville to slander nationalists.

Gosar proposed the conspiracy theory about the rally — a march that prompted demonstrations against racism, including one where a White supremacist killed one woman — in an interview published Thursday with Vice News.

“You know George Soros is one of those people that actually helps back these individuals. Who is he? I think he’s from Hungary. I think he was Jewish. And I think he turned in his own people to the Nazis,” Gosar continues. “Better be careful where we go with those.”

Soros was 14 in 1945, when the war in Europe ended.

Asked directly whether he thinks Soros funded the neo-Nazis, Gosar replied, “Wouldn’t it be interesting to find out?”

Soros’ Open Society Foundation responded to Vice News in a statement, condemning Gosar for his remarks.

“Such baseless allegations are insulting to the victims of the Holocaust, to all Jewish people, and to anyone who honours the truth. It is an affront to Mr. Soros and his family, who against the odds managed to survive one of the darkest moments in our history,” a spokeswoman wrote in a statement published by The Hill news site.

Gosar is now the second House Republican to publicly state the belief that white supremacist violence in Charlottesville was organised or funded by left-wing organisers. Last month, Rep. Dana Rohrabacher (R-Calif.) blamed the violence on “left-wingers” manipulating “dumb Civil War re-enactors.”

In Europe, many right-wing politicians and their followers have criticised Soros for his support for immigration into Europe, including by people from the war-torn Middle East and Africa.

Earlier this week, the government of Hungary, led by the rightwing Fidesz party of Prime Minister Viktor Orban, began publishing in media what it calls the “Soros Plan” national consultation — a government-led survey for voters on their perceptions on statements by Soros on immigration and the arrival of over 2 million people from the Middle East into Europe since 2014.

Eerier this year, Soros said: “Our plan treats the protection of refugees as the objective and national borders as the obstacle.”

Some Hungarian Jews claim the government’s rhetoric against Soros risks increasing anti-Semitic sentiment, though other Jews and their communal leaders dismiss these claims as exaggerated and unfounded.

Israel’s ambassador to Hungary, Yossi Amrani, in July published a statement endorsing the government’s critics. But the following day Israel’s foreign ministry said it does not view as illegitimate criticism of Soros, “who continuously undermines Israel’s democratically elected governments by funding organisations that defame the Jewish state and seek to deny it the right to defend itself,” the ministry said.

Soros is also featured in an elections campaign in neighbouring Austria. The Alpine nation will go to the ballots on Oct. 15 to elect a new chancellor. The news site Profil reported that that a leftwing politician, Sebastian Kern, was running secretly a negative campaign designed to discredit his rightwing rival, Sebastian Kurz, in the eyes of right-wing voters. Kern hired briefly Tal Silberstein, an Israeli political adviser and expert in negative campaigning.

It is not clear whether Silberstein was involved in claims made in the negative campaign that Kurz was in fact part of the “dubious political network” of Soros, as claimed in one nationalist-agenda website that Kern  reportedly had set up to hurt Kurz.