The Polish government is contemplating withdrawing a medal from a leading Jewish historian who said Poles were complicit in Nazi war crimes during the Holocaust.

Jan Tomasz Gross, a Poland-born, Jewish-American Princeton University history professor, was awarded the Order of Merit of the Republic of Poland in 1996 for his work documenting the plight of Jews in Nazi-occupied Poland.

He is best known for his 2001 book “Neighbors,” which later inspired the 2012 film “Aftermath,” and which addresses the responsibility of local residents of the village of Jedwabne for the massacres of Jews during the Holocaust.

Gross’s allegation angered Polish nationalist leadership, who claim there is too little evidence to support his assertions which they say harm the country’s reputation by portraying Poland as a perpetrator as opposed to being a victim of Nazi occupation.

A spokesperson for the Foreign Ministry called Gross’s articles “historically untrue, harmful and insulting to Poland.” However, academics rushed to defend Gross, arguing that retracting the award endangers the freedom of scientific research.

“The government says Gross is unpatriotic. But he is a patriot who looks at both the darker and lighter periods in Polish history,” wrote University of Ottawa history professor Jan Grabowski, according to The Guardian.

The re-evaluation of the national honor comes as Poland draws up new regulations to punish the use of the phrase “Polish death camps” in reference to Nazi death camps on Polish soil.