A 34-year-old man was shot on a university campus while protesting over a speech by the controversial right wing Breitbart News journalist Milo Yiannopoulos.

Police are investigating the incident at the University of Washington-Seattle campus and the victim, whose identity has not yet been made public, remains in a serious condition. The victim is being treated at the Intensive Care Unit at Harborview Medical Center in Seattle.

The victim was a member of the Industrial Workers of the World (IWW), which describes itself as a “union for all workers” and an “anti-racist, anti-fascist organisation”.

Milo Yiannopoulos, 'alt-right' columnist and internet personality (Getty)

According to a statement from the group, members were on campus last Friday to protest over Mr Yiannopoulous’ rhetoric because it “encourages violence towards minority groups.” The victim was unarmed at the time of the shooting.

Approximately 80 Seattle police officers were brought in to supplement the 25 university police staff for the event, during which several people were hit with paint and people were throwing bricks.

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Police Maj Steve Rittereiser told the Seattle Times that the alleged shooter, accompanied by another person, had turned himself in. The shooter has reportedly claimed self-defence and said that the union member who was shot was in truth a white supremacist who was being aggressive towards him. Both the alleged shooter and the person accompanying him were released pending an investigation and a consultation with the King County Prosecuting Office.

Mr Yiannopolous, no stranger to backlash for his views, had previously been banned from social media platform Twitter due to repeated use of misogynistic and racist language.

The editor’s $250,000 book deal with publisher Simon & Schuster was also met with criticism on social media and calling for the company to drop him.