Volkswagen CEO Herbert Diess is under fire for apparently making a Nazi reference while talking about his company’s earnings during an event in Germany.

Diess used the phrase “Ebit macht frei,” which is similar to “Arbeit macht frei” a phrase inscribed in Nazi concentration camps, meaning “work sets you free.”

Diess said the link between the two was unintentional and penned a blog post on Linkedin apologizing.

“Trademarks with a high return have experience that they have a higher degree of freedom of choice within the Group,” Diess said in the post. “That is what my statement referred to.”

Volkswagen has a deep, complicated history in Germany. It was one of many companies that benefitted from slave labor in concentration camps and was originally founded as a state-run automobile company in Germany. The company’s founder, Ferdinand Porsche, was a member of the Nazi Party and had the support of Adolf Hitler.

“It was in no way my intention to put this statement in a false context. That this possibility exists, I did not think of that at this moment,” Diess said in the post. “In fact, it was a very unfortunate choice of words and if I had unintentionally hurt feelings with it, I am extremely sorry.”

Volkswagen has been vocal about addressing its links to the Holocaust. It holds memorial events and offers support to those impacted from its early relationships with the Nazi Party.

Diess has been CEO of the company since April of last year.