Washington (AFP) - US comedian Louis C.K., whose glittering career famously tanked after he admitted to sexual misconduct, was in the headlines again after an audio clip from a comeback set emerged in which he mocked school shooting survivors and non-binary people.

The two-minute clip, which was uploaded to Twitter on Sunday, marks a hard right turn for C.K., who until his downfall in 2017 was feted as one of the greatest comedians of his generation and known for a liberal outlook.

According to screenshots from YouTube, where an extended version of the clip was originally posted before being taken down, the set took place on December 19.

The venue was not immediately clear, but C.K. has been making a relatively low-key comeback in recent months, performing at Manhattan comedy clubs as well as in Paris, home to his new girlfriend, French comedian Blanche Gardin.

C.K. begins by taking aim at today's youngsters, ridiculing their political correctness and telling his audience their lives are "just boring" compared to the drug-fueled antics of his time.

"They're like royalty, they tell you what to call 'em!" he says, before adopting a high-pitched, mock-gay voice to convey what non-binary people sound like according to him.

"'You should address me as they/them. Because I identify as gender neutral.'"

Returning to his normal voice to signify his response, he continues: "Okay. You should address me as 'there,' because I identify as a location," adding that location is their mother's genitalia.

- Right-wing praise -

He then turns on the survivors of the Parkland school massacre, many of whom became gun-control activists in the aftermath of the February 2018 shooting by a lone gunman that left 17 dead.

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"They testify in front of Congress, these kids? What are they doing? You're young! You should be crazy! You should be unhinged! Not in a suit," he said.

"You're not interesting. Because you went to a high school where kids got shot? Why does that mean I have to listen to you? Why does that make you interesting? You didn't get shot. You pushed some fat kid in the way, and now I've got to listen to you talking?"

Another part of the set uploaded by Swiss journalist Aicha Kottmann featured an extended take on children with learning difficulties in which C.K. repeatedly utters an offensive word to describe their condition.

The clip drew many shocked reactions even as some conservative commentators showered it with praise.

"I'm listening to the leaked Louis set and it's very clear he's just going to tour Red States for the rest of his life to rapturous crowds, like Trump," wrote comedy writer Jack Allison, who uploaded the Twitter clip.

But a rightwing commentator wrote: "Louis C.K. 2.0 is funny as hell!"

C.K.'s mainstream career went up in flames in November 2017 after he was forced to admit to masturbating in front of several women.

He was dumped by Netflix, his publicist, the television networks FX and HBO, while a movie project about the relationship between an aging filmmaker and a teenage girl was scrapped.