The Natural History Museum in London has issued an apology for renting out its building to the right-wing nonprofit National Conservatism, which has drawn criticism for its extreme views on immigration, religion, and climate change, for a gala last month.

Members of National Conservatism convened at the museum on May 15 for the event, which was part of the populist political group’s annual three-day NatCon conference. The night’s keynote speaker was Douglas Murray, a British author of books criticizing modern attitudes toward race, gender, and faith.

Murray drew backlash for evoking the Holocaust during the gala. “I don’t see why no one should be allowed to love their country because the Germans mucked up twice in a century,” he said at the event. National Conservatism shared that quote on social media with a picture of Murray standing below the museum’s iconic Hope the Whale skeleton. 

In a blog post published on June 1, two weeks after the gala, the museum said it was “horrified and saddened to see hateful rhetoric being expressed” at the private event. 

“Had we anticipated some of the rhetoric that was expressed at the event, we would not have permitted it to be held on our site. We should have anticipated this, but because of a genuine mistake our usual processes were not followed, and we take full responsibility for this,” the post read. 

“It was particularly painful to see an image of Hope the Whale used to illustrate a tweet alongside rhetoric that minimized the horrors of the Holocaust,” it went on. “We didn’t call out and reject these posts as we should have done when they were first published and gathering attention.” 

“We want to make clear that we utterly abhor the statements made and we are sorry they were shared with imagery of the museum.” It added that museum employees were discussing how to best use the proceeds from the event. 

Representatives from the museum did not immediately respond to a request for comment.

National Conservatism was launched by the Edmund Burke Foundation, a right-wing think tank based in Washington, D.C. The populist-nationalist beliefs of the foundation’s chair, Yoram Hazony, are thought to have heavily informed former President Donald Trump’s foreign affairs strategies.