The Morrison government has banned right-wing provocateur Milo Yiannopoulos from entering Australia in a fresh crackdown likely to infuriate his conservative supporters but please critics who believe he is anti-Semitic.

The Sydney Morning Herald and The Age can reveal the controversial speaker was told this week his visa application had been rejected and he cannot enter Australia.

Milo Yiannopoulos has been banned from entering Australia. Alex Ellinghausen

He has a month to appeal the Department of Home Affairs decision, which was made on character grounds.

In June last year Paypal suspended Yiannopoulos after he used the online payment system to send $14.88 to a Jewish journalist.

The number 1488 is used by white supremacists and neo-Nazis because '14' represents the mantra of securing a future for white children and '88' represents "Heil Hitler".

The same month he sent threatening text messages to journalists, stating: "I can’t wait for the vigilante squads to start gunning journalists down on sight."

The 33-year-old confirmed he wrote the messages but said that he sent them to the reporters as a way to troll them.

A letter sent to Yiannopoulos by immigration officials foreshadowed this week's final decision.

The letter noted Australia had the power to block someone from entering the country if there was a risk that person would "incite discord in the Australian community or in a segment of that community".

The letter was released by one of Yiannopoulos' strongest supporters, Sky News host Andrew Bolt, earlier this month.

The government has banned a number of controversial people from entering the country in recent years, including WikiLeaks whistleblower Chelsea Manning and Gavin McInnes, the leader of the far right Proud Boys group.

It last month also banned notorious English conspiracy theorist David Icke from entering the country for a planned speaking tour.

At least five police officers injured in clash.

Among the bizarre claims made by Icke, a former footballer and BBC sports presenter, are that the world is controlled by a cabal of giant shape-shifting reptiles, many of them Jewish, and that a group of elite Jews bankrolled Adolf Hitler and started several wars.

He also tells audiences the September 11 attacks were an inside job organised by "a network that works through government agencies, through organisations like the CIA".

A five-show tour of Australia scheduled for December 2018 was cancelled at the last minute due to "unforseen circumstances". He and conservative speaker Ann Coulter planned to discuss the topic "how to save Australia".

Yiannopoulos spoke at Parliament House in Canberra in 2017 at a function attended by former senator David Leyonhjelm​ and One Nation leader Pauline Hanson.

During his 2017 visit several protesters were arrested after clashing with police and fans outside one of his secret Sydney speaking events.

Senator Hanson has been pushing Immigration Minister David Coleman to grant Yiannopoulos and British far-right figure Tommy Robinson a visa.

"I first wrote to minister Coleman a month ago and he assured me he would respond but it seems like the government is too afraid to take a stand because now he is dodging me," the One Nation leader wrote on Facebook.

"I’m sad to say the government is now acting as an arm of Antifa. Milo and Tommy have not called for violence. They have been the victims of violence. By refusing them entry into Australia this gutless government is validating the left's use of violence to silence people."