A petition to block Milo Yiannopoulos a visa to enter Australia is gathering steam after the self-described "right-wing agitator" and anti-feminist announced a tour in recent days.

Yiannopoulos was a leading light of the alt-right movement, but his advocacy of paedophilia saw him forced from fringe right news site Breitbart in February.

Now he has announced a tour of Australia, speaking at "secret CBD locations to be advised seven days before the event".

Immigration Minister Peter Dutton 's office was not aware of Yiannopoulos's visit when contacted by nine.com.au, and is now considering whether it will deny him a visa.

Speaking on podcast Drunken Peasants last year, Yiannopoulos spoke in favour of sexual relationships between adults and children.

"There are certainly people who are capable of giving consent at a younger age, I certainly consider myself to be one of them, people who are sexually active younger.

"Some of those relationships between younger boys and older men, the sort of coming of age relationships, the relationships in which those older men help those young boys to discover who they are, and give them security and safety and provide them with love and a reliable and sort of a rock where they can’t speak to their parents…"

Yiannopoulos was cut off by one of the radio hosts who described it as "Catholic priest molestation".

Milo Yiannopoulos speaks at an event in Colorado. (AAP)

Yiannopoulos would then instruct the hosts on the definition of paedophilia, saying it specifically referred to sexual attraction of pre-pubescent children.

Another video later emerged in which he described child abuse as "not that big of a deal" and said victims were "whinging selfish brats".

His tour of Australia in December includes appearances in Adelaide, Perth, Melbourne, Sydney and the Gold Coast.

It is sponsored by pornographic magazine Penthouse.

"Whether it was Martin Luther King and the freedom riders in the 1960’s or Milo Yiannopoulos in 2017, free speech is part of Australia’s robust democracy and the cornerstone of Western civilisation," Penthouse publisher Damien Costas said.

The tour also includes an opportunity to have a private dinner with Yiannopoulos, limited to 20 guests.

"The world has changed over the last two years with Brexit and Donald Trump and I think Milo talks a lot of common sense, as does Andrew Bolt and Mark Latham," PR agent Max Markson told Mumbrella.

"Milo is amazing. He is incredibly articulate, witty, funny and politically incorrect."

Protesters gather at University of California, Berkeley, over a speech by Milo Yiannopoulos. (AAP)

In 2016 he penned an article for Breitbart slamming activists for speaking about "college rape culture".

"This isn't about protecting women. It's about man-hating," he wrote.

"It's a campaign aimed squarely at undermining masculinity."

Yiannopolous was banned from Twitter for instigating abuse at Ghostbusters actress Leslie Jones.

Visa applications are normally granted or denied by the Department of Immigration, but the minister can intervene if he sees fit.

Boxer Floyd Mayweather, singer Chris Brown and "pick-up artist" Julien Blanc were all denied entry to Australia for their history of violent behaviour or advocacy towards women.

Milo Yiannopoulos's Facebook post. (Facebook)