Volkswagen chief executive Herbert Diess in Barcelona on March 27. (Angel Garcia/Bloomberg News)

A JOINT venture based in Shanghai, SAIC Volkswagen, is one of the oldest such automakers in China, with production based in several cities across the country, including in Xinjiang, home to ethnic Muslim Uighurs and other minorities in China’s far northwest. The joint venture says it “strives to be a responsible corporate citizen,” concerned about the environment, and “returning to society and benefiting the society” with “social welfare undertakings in the fields of science, education, culture, health” and more.

So it was shocking to hear the head of Volkswagen express ignorance the other day about the systemic cultural genocide unfolding in Xinjiang. There, Chinese authorities are carrying out a brazen attempt to extinguish the traditions, language and mind-set of the Turkic Muslim minority, including Uighurs, Kazakhs and others, stamping them into the mold of the majority Han Chinese. An estimated million or more people have been confined in an archipelago of camps that China describes as vocational education facilities or boarding schools — but others, including eyewitnesses, say are concentration camps.

Asked by the BBC whether he is "proud to be associated" with Chinese repression in Xinjiang, Volkswagen chief executive Herbert Diess said, "No, but we are proud to create . . . we are absolutely proud to also create workplaces in that region, which we think is very useful." Pressed about China's maltreatment of the Uighurs, Mr. Diess added, "I can't judge this, sorry." Then, asked whether "you know about it," he said, "I don't know what you're referring to." When a reporter pressed him about China's establishing reeducation camps for a million people in Xinjiang, Mr. Diess said, "I'm not aware of it."

This cannot be true. As the leader of a multinational corporation with factories spread across China, he must know of the atrocity unfolding in Xinjiang. His comment is abhorrent, and just as disturbing is the possibility that his remarks reflect ambivalence by SAIC Volkswagen about the treatment of the Uighurs and others. Has this joint venture, formed in 1984, soon after China’s reform era began, been looking the other way as China extinguishes the customs and mind-set of a whole population? China has vigorously attempted to cover up the concentration camps in Xinjiang in the past few months. Eyewitnesses and experts report that, in addition to the camps, Xinjiang has been turned into a laboratory for using surveillance to closely monitor the population so as to quickly smother any signs of dissent. A large company such as SAIC Volkswagen must not remain indifferent to the concentration camps, and certainly a chief executive from Germany should not pretend they don’t exist.

After Mr. Diess spoke, Volkswagen said the company “is aware” of the plight of the Uighurs and has taken positive steps to address it. “For the whole Volkswagen Group, respecting human rights is one of the fundamental basic principles for all business relationships,” the spokesman said. If so, then Mr. Diess needs to speak up against China’s drive to crush the Uighurs and other Muslim minorities. To remain “not aware” is to remain complicit.