Historians fear that mounting pressure against scholars who implicate Poles in the Holocaust is having a chilling effect on research across Europe, with one France-based researcher saying she will tone down her upcoming book and shy away from naming names.

Audrey Kichelewski, an associate professor of contemporary history at the University of Strasbourg who is writing a book about postwar trials of Poles, said she would be “very cautious with the vocabulary” she used and would not cite defendants’ names for fear of being sued by living relatives.

It is the latest episode in what critics say is a concerted effort by Poland’s right-wing government and supportive groups to aggressively enforce a narrative of exclusive victimhood, stressing the heroic stories of Poles who risked their lives to save Jewish compatriots but downplaying accounts of complicity in the Holocaust unearthed by some historians.

A 2018 legal amendment would have threatened jail for those who implied the Polish “state” or “nation” was complicit in Nazi crimes, although the law was repeatedly watered down after an international outcry and stripped of its criminal component.

In February, a Warsaw court ordered two scholars -- Barbara Engelking, director of the Polish Center for Holocaust Research, and Jan Grabowski, professor of history at the University of Ottawa -- to apologize after they detailed the case of a mayor of a Polish village who allegedly betrayed a group of Jews to Nazi occupiers.

In the same month, a Polish journalist revealed that she was questioned by police for writing that Polish complicity in the Holocaust was a “historical fact,” although the case was later dropped.

And last month, an ultraconservative Polish Roman Catholic group threatened to sue a French radio station for “infringing the reputation of the republic of Poland” by supposedly implicating Poland in Nazi war crimes during a program.

The Polish League Against Defamation, which backed the case against Engelking and Grabowski, has launched lawsuits against newspapers and broadcasters in Germany, Italy and Spain, invoking concepts such as a right to “national pride” for Poles.

Several leading researchers issued warnings about the impact of the pressure on Holocaust research.

“I am afraid the chilling effect is already there, but I cannot prove it, as it is invisible, by definition,” said Dariusz Stola, professor of history at the Institute of Political Studies of the Polish Academy of Sciences.