(JTA) — The World Jewish Congress is being criticized in Ukraine for partnering with an organization whose leader is accused of spreading conspiracy theories to downplay concerns about anti-Semitism.

Eduard Dolinsky, the director of the Ukrainian Jewish Committee, criticized the World Jewish Congress Thursday with regards for its co-organizing next week a conference in Ukraine about Yiddish with the Vaad Association of Jewish Organizations and Communities of Ukraine.

The event is an international commemorative conference of Yiddish language and culture slated to open next week in Chernivtsi as part of the Jewish Culture Days in Bukovina festival.

“It is not okay, WJC are working with a compromised organization that is undermining the Jewish community,” Dolinsky said of Vaad, adding that group is mouthpiece for the Ukrainian government, on which he said Vaad is “politically manipulated and dependent.” Vaad, Dolinsky added, “whitewash” rising anti-Semitism in Ukraine and the glorification of Nazi collaborators.

Vaad’s executive co-president, Josef Zissels, rejected this criticism, stating his organization is Ukraine’s most independent and active Jewish group, and that it regularly condemns what it deems genuine expressions of anti-Semitism. Zissels said Donlinsky’s allegations “are lies and slander in order to diminish the authority and influence” of Vaad.

Contacted by JTA, a WJC spokesperson said that Vaad is only one of several partners involved in the Yiddish event, including the Ukrainian Jewish Encounter and the University of Chernivtsi. The spokesperson’s reply did not directly address Dolinsky’s criticism of her organization’s cooperation with Vaad.

In May, Zissels dismissed as Russian-bought propaganda a letter by more than 50 U.S. Congressmen who warned against Ukraine’s “glorifying of Nazi collaborators” and the “rise of this hateful ideology” in Ukraine. Subsequently, the Euro-Asian Jewish Congress, a regional affiliate of WJC, ended its relationship with Vaad, a former affiliate of the Euro-Asian Jewish Congress.

That month, more than 40 Jewish communal leaders in Ukraine, including Dolinsky’s group and Ukraine’s Hillel Jewish student organization, signed a joint statement condemning the rise in anti-Semitic crimes in Ukraine and declaring that Zissels and Vaad “do not represent the Jews of Ukraine” and “do not express the position of the Jewish community of Ukraine.”

In January, an Israeli government report on anti-Semitism singled out Ukraine as a trouble spot. An author of the report said Ukraine had more than 130 anti-Semitic incidents in 2017, more than any other former Soviet country and more than all anti-Semitic incidents in all former Soviet countries combined.

But a Vaad researcher dismissed the report as flawed, adding it showed “blatant lack of professionalism and violation of all standards of hate crimes documentation.”

A revolution in 2013 that ended the rule of a key Kremlin ally in Ukraine ushered in a wave of nationalism. It features the glorification of fighters who allied with the Nazis against Russian domination. In 2015, the Ukrainian Parliament passed a law that criminalizes denying the “heroism” of some of these allies of Nazi Germany, which oversaw the near annihilation of the region’s Jews.

In April, hundreds of people in the Ukrainian city of Lviv attended a nationalist march featuring Nazi symbols that commemorated a Waffen SS unit with many local volunteers.