Polish prosecutors have opened an investigation into a Swedish artist’s claim that he used the ashes of Holocaust victims to make a painting that was displayed in a gallery in Lund, Sweden.

The artist, Carl Michael Hausswolf, wrote on the website of the gallery last year that he made the painting using ashes that he had taken from crematorium furnaces in Majdanek, a former Nazi German death camp near Lublin in eastern Poland, on a visit there in 1989.

The Nazis exterminated more than 79,000 people at the facility between 1941 and 1944, most of them Polish Jews.

Spokeswoman Beata Syk-Jankowska for the Polish prosecutor’s office said on Tuesday that local prosecutors had begun investigating whether there was truth to Hausswolf’s claim. She said there was no evidence and prosecutors were acting on media reports. Swedish investigators will be asked for assistance.

If Hausswolf’s claims are found to be true, he could be charged in Poland with desecrating human ash or a resting place.

Hausswolff stirred up international controversy in early December amid media reports of his morbid work.

Salomon Schulman, a Jewish community leader who said he had lost relatives to the Nazi death machine, condemned the painting as “revolting” and said he would boycott the gallery where the work was on display.

“Who knows, maybe some of the ashes originated from my relatives,” Schulman wrote in an op-ed in the Swedish newspaper Sydsvenskan. “No one knows where they were deported: all my mother’s siblings and their children, and my grandparents.”

Schulman said he was “sickened” by von Hausswolff’s work and “obsession with necrophilia.”

The artist at the time defended his use of the ashes, claiming they contained “the memories and the souls of people: people tormented and murdered by other people in the most vicious war of the 20th century.”

Martin Bryder, the owner of the Lund gallery, invited Schulman to come view the painting and “judge for himself.”

“Mr Schulman has already declared in the papers that he won’t come and see it, but if he did, perhaps he would have a different opinion,” Bryder told the Polish Press Agency.

Later, Bryder canceled the exhibition, telling Sydsvenskan that he made the decision because of protests by the Simon Wiesenthal Center and the Jewish community of Malmo.

The Simon Wiesenthal Center had called the painting a “desecration” and “abomination.”

“I think pulling the exhibition was the right decision,” said Shimon Samuels, the Simon Wiesenthal Center’s director of international relations. “I would further insist the painting be returned to Majdanek for burial there.”

AP and JTA contributed to this report.