YouTube’s biggest star, Felix “PewDiePie” Kjellberg, used a racial epithet on Sunday in an expletive-laden outburst during one of his popular livestreams.

The Swedish web personality was broadcasting himself playing the survival game “PlayerUnknown’s Battlegrounds” when he used a derogatory word for African-Americans.

“What a f—–g n—–!” Kjellberg said. “Jeez! Oh my god! What the f—? Sorry, but what the f—?”

Here’s a clip of the moment:

Kjellberg was streaming the game on his YouTube channel, which has more than 57 million subscribers and is the platform's most popular by far. The livestream was being viewed by more than 30,000 people when he used the racial slur.

After Kjellberg uttered the slur, he said, "I don't mean that in a bad way," before trailing off and laughing again.

Though Kjellberg usually leaves his livestreams up as archived sessions after they're over, this one - titled "CALIFORNIA ROLL" - isn't available.

This isn't the first time Kjellberg has used stirred controversy. Earlier this year, the Wall Street Journal published a story detailing several instances of Kjellberg using anti-Semitic imagery and phrases in his videos.

Foto: A screenshot from a video by Felix Kjellberg, also known as PewDiePie. source YouTube

As a result of that report, a deal with Disney and a produced YouTube show starring Kjellberg were canceled.

And already on Sunday evening, at least one prominent video game developer said his company's games won't be allowed for use in future PewDiePie videos.

"I am sick of this child getting more and more chances to make money off of what we make," Sean Vanaman, co-founder of the game studio Campo Santo and co-director of the popular game "Firewatch," wrote on Twitter. "He's worse than a closeted racist: he's a propagator of despicable garbage that does real damage to the culture around this industry."

Kjellberg's stream of "Firewatch," which Vanaman said had around 5.7 million views, has seemingly already been taken down.

"We're complicit," Vanaman wrote. "I'm sure we've made money off of the 5.7M views that video has and that's something for us to think about."

It's unclear how YouTube will respond, if at all. A request for comment was not immediately returned on Sunday.