Alt-right commentator Milo Yiannopoulos has stepped down from the US website Breitbart News after days of controversy over his comments about sexual relationships between boys and older men.

Previously run by Trump adviser Steve Bannon, Breitbart News is considered by many a platform for the so-called “alt-right” movement, an offshoot of conservatism that mixes racism, white nationalism and populism.

Yiannopoulos, 32, said at a news conference on Wednesday he was quitting as editor of Breitbart Tech because it would be wrong “to allow my poor choice of words to detract from my colleagues’ important reporting”.

Milo Yiannopoulos, a conservative columnist and internet personality.

“I regret the things that I said,” Yiannopoulos said, while calling the furore over his comments a “cynical media witch hunt”.

Earlier, the influential Conservative Political Action Conference withdrew a speaking invitations while publishers Simon & Schuster announced it would not publish his new book, Dangerous.

On Wednesday, Yiannopoulos said other publishers were interested in his book and announced he would launch a new media company.

Yiannopoulos had been facing increasing pressure to resign after comments he made during a 2016 podcast emerged online.

He argued in the clip that relationships between “younger boys and older men” could be beneficial.

Discussing the issue of consent, Yiannopoulos referred to “coming of age” relationships which occur “in the homosexual world, particularly”.

“Those older men help those young boys to discover who they are and give them security and safety and provide them with love,” he said.

Yiannopoulos sparked protests at UC Berkley earlier in the month. Photo: Getty

He directly referred to contact between 13-year-old boys and older men.

Yiannopoulos also referred to abuse he himself experienced when he was a child, saying, “I’m grateful for Father Michael. I wouldn’t give nearly such good head if it wasn’t for him.”

The 33-year-old has risen to prominence on the back of provocative statements about feminists, Muslims and Black Lives Matter activists, which have been labelled sexist and racist.

Others have lauded him as a champion of free speech whose courting of controversy provides an antidote to political correctness.

His appearances on college campuses have sparked protests, including a demonstration earlier in February that turned violent at University of California at Berkeley, forcing the event’s cancellation.

-with AAP, ABC