A film showing artists playing naked tag inside the gas chamber at a former Nazi concentration camp in Poland has outraged Holocaust survivor groups — and now they’re demanding answers from the country’s leader.

The film “Game of Tag” was shot in 1999 by Artur Żmijewski at the former Stutthof camp, where 65,000 people were slaughtered, and exhibited at the Museum of Contemporary Art Krakow in 2015.

But the location of the film at Stutthof, near Gdansk, was not known until this year after a visit by Britain’s Prince William and wife Kate Middleton, the BBC reported.

Jerusalem-based lawyer David Schonberg noticed that footage from the royals’ July visit showed the same stains on the walls and other features.

The exhibit was sponsored by the Israeli embassy, which called for part of the video to be removed after Jewish groups protested. But the museum said it should be shown as a matter of freedom of expression.

The Simon Wiesenthal Center, the Center Organizations of Holocaust Survivors in Israel and other groups sent President Andrzej Duda a letter Wednesday, the Times of Israel reported.

“Extensive research recently revealed that the site where the video was filmed is the gas chamber at the Stutthof concentration camp, and it is this discovery which prompted the demand for clarifications from the Polish leaders and the administration of the Stutthof concentration camp site (and museum),” the letter said.

The groups asked Duda to “clearly, properly condemn this so-called artwork.”

They also asked whether the artists obtained permission from Stutthof administrators to make the video, “what rules exist for proper conduct at the site, how these are enforced” and whether an investigation was launched, the Simon Wiesenthal Center said.

“It’s really outrageous. I hope the Polish president will put in place regulations to make sure stuff like this doesn’t happen again,” Efraim Zuroff, the Wiesenthal Center’s chief Nazi hunter, told the BBC.

“It was banned in Germany, Estonia took it down when we contacted them. In Poland for some reason, which lost 6 million people — 3 million Jews and 3 million Poles — they didn’t get it,” he added.

Schonberg told the BBC that Poland’s “apparent indifference” to the video was more galling than the footage itself.

“This is a problem that needs to be addressed. If people are not sufficiently sensitive to the terrible acts of the Holocaust and do not respect its victims, then proper conduct in the sites in Poland cannot be properly secured,” he said.

“This also requires proper scrutiny of these sites and making sure that objectionable materials that are so insensitive to the memory of the Holocaust will not be brought on public display.”