Controversial congressional contender Paul Nehlen was permanently banned from Twitter on Monday, following an outcry over a racist tweet he posted featuring Prince Harry’s fiancée, Meghan Markle.

Nehlen’s tweet featured an image in which the head of “Cheddar Man” – a 10,000-year-old skeleton discovered in Britain at the turn of the 20th century – was superimposed over Markle’s. A recent DNA analysis showed that Cheddar Man had black skin, stunning the many who assumed he was light-skinned.

Nehlen is challenging House Speaker Paul Ryan in Wisconsin’s 1st Congressional District GOP primary this August, but has attracted criticism following months of blatantly anti-Semitic and racist tweets.

A Twitter spokesman told media outlet Madison365: “While we normally do not comment on individual accounts, I can confirm that we have permanently suspended this account for repeated violations of our terms of service.”

Nehlen’s tweets boosted his profile among white nationalists, but resulted in a break with some in the so-called alt-right community – most prominently Breitbart News and its former head, Steve Bannon. Bannon had supported Nehlen’s challenge to Ryan in the GOP 2016 primary, a race Nehlen lost by more than 70 percentage points.

Before his Twitter account was suspended, Nehlen defended his Markle tweet, saying the “Cheddar Man” study represented efforts by scientists to “prove whites never existed.

“I made a joke of it,” he said. “It’s not a laughing matter, so I chose to laugh about it.”

While Twitter does not publicly reveal the reasons for suspending or banning users (Nehlen’s account has been suspended for brief periods before), the global outcry over his Markle tweet has been pointed to as the last straw.

Another possible reason is a recent Nehlen tweet that included the names, telephone numbers and email addresses of his most prominent critics, and where he claimed most of them were Jewish. Some of the people featured on the list reported being harassed as a result of its publication. That tweet appeared after he had been suspended from Twitter for a week.

Following Nehlen’s “Jewish enemies list” tweet, the Milwaukee Journal Sentinel published an editorial titled “We must stand up to the small-minded, anti-Semitic bigotry of Paul Nehlen.”

It declared: “It’s time to take a stand against bigots who enter the public square. Paul Nehlen, a candidate for Congress, is a bigot. Paul Nehlen has a right under the First Amendment to say nearly any hateful thought that pops into his head. The rest of us have the right to stand up, speak out loudly against him, turn our backs in disgust at his message and show our support for our neighbors of goodwill, whatever their faith, nationality or color.”